The column of Bradley armored autos rumbled ahead, crammed with Ukrainian troopers, bringing a brand new and potent American weapon to the warfare’s southern entrance.

But then one hit a mine. The explosion blew off one of many car’s bulldozer-like tracks, immobilizing it. The complete Ukrainian column reversed course, pulling again.

Three weeks right into a counteroffensive essential to Ukraine’s prospects in opposition to Russia, its military is encountering an array of vexing challenges that complicate its plans, even because it wields subtle new Western-provided weapons. Not least is an unlimited swath of minefields defending Russia’s line of defense, forming a killing subject for Ukrainian troops advancing on the open steppe of the south.

“Everything is mined, everywhere,” mentioned Lt. Ashot Arutiunian, the commander of a drone unit, who watched by a drone’s video hyperlink because the mine exploded below the Bradley and halted the column’s advance.

Over the weekend, a mutiny on Russian soil by mercenary forces raised hopes in Ukraine that its military would possibly discover the going a bit simpler, although the insurrection shortly died out.

But Ukrainians nonetheless face hurdles that differentiate this marketing campaign from their swift push by the Kharkiv area in September and even from the extra arduous offensive that recaptured Kherson in November.

The terrain within the southeast is generally flat, open fields, in distinction to the rolling hills of the Donbas or the closely forested north, depriving Ukraine’s troops of canopy. The Russians have additionally been dug in for months in expansive trench strains, making uprooting them harder.

In addition, KA-52 Russian assault helicopters have been capable of slip previous air defenses, slowing Ukrainian actions whereas damaging or destroying Western-provided tanks and armored combating autos.

And not solely are the minefields larger and extra ubiquitous, however Russian troops have proved adept at replenishing some minefields cleared by Western-supplied tools, a senior United States army official mentioned.

Ukrainian forces in some places alongside the entrance line are pausing to reassess which breaching and clearing techniques and strategies are working finest, the official mentioned.

The fierce resistance has taken a toll on Ukraine’s weaponry. The United States dedicated 113 Bradley combating autos in March. At least 17 of them — greater than 15 p.c — have been broken or destroyed within the combating to this point, the official mentioned.

These obstacles have turned the early levels of the counteroffensive right into a gradual and bloody slog, limiting Ukraine’s forces to about 4 miles of territory gained of their farthest advance to this point. That’s lower than half the space Ukraine must cross — threatened by mines and relentless Russian artillery bombardment — to succeed in Russia’s most important defensive positions.

“They dug in, they mined, they are ready,” mentioned Yevhen, a personal with a paramilitary police unit who, like another troopers, insisted on being recognized solely his first identify and rank. “It is difficult, but there is no other option.”

Despite the counteroffensive’s gradual progress, Ukrainian officers say the principle battles to breach Russian defenses are nonetheless forward, and with the majority of Ukraine’s drive nonetheless saved in reserve, it’s early to gauge success or failure, they contend.

Mr. Zelensky, whereas conceding that progress has been “slower than desired,” cautioned in opposition to what he portrayed as unrealistic expectations of a cinematic blitzkrieg by enemy strains.

“Some people believe this is a Hollywood movie and expect results now,” Mr. Zelensky mentioned in an interview with the BBC this previous week. “What’s at stake is people’s lives,” he mentioned. “We will advance on the battlefield the way we deem best.”

In Washington, officers within the Biden administration are publicly urging endurance whilst they privately fret that the preliminary progress has been gradual. One senior administration official known as the outcomes of the primary couple of weeks “sobering,” including, “They’re behind schedule.”

The senior U.S. army official additionally acknowledged the slower-than-hoped-for tempo of operations however added that this was not surprising given the intensive Russian defenses, and cautioned in opposition to drawing any broad conclusions primarily based on the preliminary operations.

Both officers spoke on the situation of anonymity to debate confidential authorities assessments.

Ukraine is searching for to separate Russian-occupied territory within the south into two zones, reducing provide strains to the Crimean Peninsula and making a springboard for additional advances. To achieve this, it should push south about 60 miles from the previous entrance line, the place Ukraine halted Russia’s advances in March 2022, to the Sea of Azov.

Russia’s most important defenses lie a dozen or so miles behind closely defended territory. Those are probably the most troublesome to cross.

Ukraine’s technique has been to probe, hanging at a number of websites to discover a weak level in defenses. Russia, which has been making ready for the assault for months, is searching for to gradual Ukrainian troops with mines, artillery, assault helicopters and counterattacks earlier than they’ll discover a hole and ship troops flowing by it into occupied territory.

Success for Ukraine now hinges on what number of tanks, armored autos and troopers it may protect earlier than reaching the first line of defense and in a battle to interrupt by. Over the winter, Ukraine and Western allies skilled and geared up about 40,000 troopers for the assault.

“How much will they have left available at that point?” Michael Koffman, the director of Russia research at CNA, a analysis institute in Virginia, mentioned in a phone interview. “A lot of what we see so far is inconclusive.”

At two of three factors of assault, south of the city of Velyka Novosilka and the town of Zaporizhzhia, Ukraine has punched ahead little by little and reclaimed a complete of eight villages. At the third, south of the city of Orikhiv, the place the Bradley hit a mine, the assault has appeared to stall within the fields.

Curiously, Ukraine has superior within the two places the place troops have been supplied fewer new Western weapons, and stalled the place probably the most subtle new weapons — American Bradleys and German Leopard 2 tanks — have been deployed.

It’s not clear if that’s as a result of Western weaponry was deliberately deployed in areas the place there have been stiffer Russian defenses.

Local elements, troopers combating on this space mentioned, may clarify the slower progress the place Western weapons have been deployed. The nearest villages, helpful for locating deserted homes, basements and root cellars for canopy, are farther from the entrance line than at different websites.

And out within the open fields, the artillery bombardments have been so intensive, mentioned a drone pilot who flies over the realm usually, that the battlefield “looks like Swiss cheese.”

Even as they mood expectations, Ukrainian officers have insisted the battle is on observe. General Valery Zaluzhny, the commander of Ukraine’s military, revealed a video this week displaying him perusing a big map and saying the combat was going “according to plan.”

Out within the expanse of farm fields in southern Ukraine, troopers combating on the entrance or aiding in medical evacuations mentioned they understood the technique of probing assaults, and that some would succeed and others wouldn’t. But they mentioned the Russian defenses have been formidable and progress is gradual.

Lieutenant Yaroslav, a medic who has been evacuating wounded from the combating, mentioned the wounded described harrowing battles. “Given what the guys are saying, it’s not going as well as they show on TV,” he mentioned.

On one axis of assault, Ukraine has superior extra shortly than anticipated. Soldiers combating south of the town of Zaporizhzhia mentioned that they had been ordered to advance with no Western heavy weaponry. After reclaiming the village of Lobkove, the troopers discovered they have been shut sufficient to the following village, Piatykhatky, to listen to its canines barking. It wouldn’t be laborious to slide over to reclaim it, a soldier mentioned, and this was carried out final week.

At a Ukrainian gun line, the artillery officer, a lieutenant named Arseniy, rattled off the sorts of rounds Ukraine fires: shrapnel for infantry within the open, a detonator with a delay for burrowing into and blowing up bunkers, and shells crammed with leaflets explaining find out how to give up — a part of a Ukrainian psychological warfare operation to chip away at Russian morale.

On a current daybreak, after a rainstorm had blown over the night time earlier than, the gunners ready a Soviet-legacy howitzer of a sort nicknamed the Carnation. The barrel swiveled. “Fire!” a soldier yelled. The gun boomed. Leaves fluttered down from close by timber.

A couple of minutes later, the artillery staff was despatched by an intelligence unit an intercept of Russian walkie-talkie communications. “Probably two dead,” a Russian commander mentioned. The troopers have been in a buoyant temper.

“It’s our usual working day to destroy as much as possible,” Arseniy mentioned.

Of the counteroffensive, which he sees by the ebb and move of orders to fireside the gun, he mentioned, “I think it is going to plan,” however then added, “Even if things go not according to plan, that is also in our plan.”

The as soon as sleepy nation roads, lined with tall inexperienced grass and wildflowers, are actually clogged with ambulances leaving the entrance, their lights flashing. Tracked autos rumble alongside, and pickup vehicles spray painted with makeshift camouflage, the principle transport for troopers, bounce over the ruts.

As twilight pale into night time, and swallows swooped and screeched over the fields, a Ukrainian drone surveillance unit hooked up to the forty seventh Mechanized Brigade went to work.

These first hours of night time are prime time for searching Russian tanks with infrared cameras, because the cumbersome steel armor, warmed within the solar by the day, all however glows in the dead of night.

“Sunset is our golden time,” mentioned the commander, Lt. Arutiunian. The troopers spot tanks, then name in coordinates to an artillery staff.

“We are testing their defenses” mentioned Lt. Arutiunian. “I would not call it a full-scale attack yet,” he mentioned. “We are probing.”

Andrew E. Kramer reported from Zaporizhzhia, Ukraine, and Eric Schmitt from Washington.