KYIV, Ukraine (NewsNation) — U.S. officials pledged Monday to ensure Ukraine wins its fight against Russia following in-person visits with President Volodymyr Zelenskyy as Russia failed to make a significant breakthrough Ukraine’s eastern region.

Secretary of State Antony Blinken and U.S. Defense Secretary Lloyd Austin said in talks with Zelenskyy that the United States had approved a $165 million sale of ammunition for Ukraine’s war effort, along with more than $300 million in foreign military financing. Their three-hour meeting Sunday marked the 60th day since the start of the invasion.

“When it comes to Russia’s war aims, Russia is failing. Ukraine is succeeding. Russia has sought as its principal aim to totally subjugate Ukraine, to take away its sovereignty, to take away its independence. That has failed,” Blinken said.

Russian Foreign Minister Sergei Lavrov said weapons supplied by Western countries “will be a legitimate target,” adding that Russian forces had already targeted weapons warehouses in western Ukraine.

“Everyone is reciting incantations that in no case can we allow World War III,” Lavrov said in a wide-ranging interview on Russian television. He accused Ukrainian leaders of provoking Russia by asking NATO to become involved in the conflict.

By providing weapons, NATO forces are “pouring oil on the fire,” he said, according to a transcript on the Russian Foreign Ministry’s website.

Regarding the possibility of a nuclear confrontation, Lavrov said: “I would not want to see these risks artificially inflated now, when the risks are rather significant.”

“The danger is serious,” he said. “It is real. It should not be underestimated.”

As fighting continued, Russian forces struck deep into Ukraine, targeting infrastructure far from the front lines, according to Ukrainian and Russian reports.

In a series of new strikes on Ukraine’s railways, a Russian missile hit one facility near Krasne, outside the western city of Lviv, early Monday, sparking a fire, the region’s governor said. A total of five railway facilities in central and western Ukraine were hit by Russian strikes, said Oleksandr Kamyshin, the head of the state-run Ukrainian Railways.

At the same time, Serhiy Borzov, the governor of Ukraine’s central Vinnytsia region, said there were casualties after rocket strikes targeting “critical infrastructure.” It was not clear if those strikes were related to the attacks on the railways.

Also Monday, Russia destroyed an oil refinery in Kremenchuk in central Ukraine, along with fuel depots there, Russian Defense Ministry spokesman Maj. Gen. Igor Konashenkov said.

He added that other strikes by long-range missiles overnight hit concentrations of troops and weapons and ammunition depots in Barvinkove and Nova Dmytrivka in the Kharkiv region, near the Russian border. In all, he said Russian warplanes destroyed 56 Ukrainian targets.

In the Russian region of Bryansk, a fire erupted early Monday at an oil depot, but no immediate cause was given for the blaze in oil storage tanks. NASA satellites that track fires showed something burning at coordinates that corresponded to a Rosneft facility some 70 miles north of the Ukrainian border. Moscow previously has blamed Ukraine for attacks in Bryansk.

Britain’s Ministry of Defense said Monday that Ukrainian troops holed up in a steel plant in the Mariupol were tying down Russian forces, and keeping them from being added to the offensive elsewhere in the Donbas.

“Many Russian units remain fixed in the city and cannot be redeployed,” the ministry said in a statement posted on Twitter. “Ukraine’s defense of Mariupol has also exhausted many Russian units and reduced their combat effectiveness.”

The ministry added that, so far, Russia has only made “minor advances in some areas since shifting its focus to fully occupying the Donbas.”

Over the weekend, Russian forces launched fresh airstrikes on the steel plant in an attempt to dislodge the estimated 2,000 fighters inside. An estimated 1,000 civilians are also sheltering in the factory.

More than 100,000 people, down from a prewar population of about 430,000, are believed to remain in Mariupol with scant food, water or heat. Ukrainian authorities estimate more than 20,000 civilians have been killed. Recent satellite images showed what appeared to be mass graves to the west and east of Mariupol.

With Russia’s shift in focus, Austin said Ukraine’s military needs are changing, and Zelenskyy is now focused on more tanks, artillery and other munitions.

“The nature of the fight has evolved, because the terrain they’re now focused on is a different type of terrain, so they need long-range fires,” Austin said.

When asked about what the U.S. sees as success, Austin said that, “We want to see Ukraine remain a sovereign country, a democratic country able to protect its sovereign territory, we want to see Russia weakened to the point where it can’t do things like invade Ukraine.”

On the diplomatic front, U.N. Secretary-General Antonio Guterres was scheduled to travel to Turkey on Monday and then Moscow and Kyiv. Zelenskyy said it was a mistake for Guterres to visit Russia before Ukraine.

In a boost in support for Ukraine, French President Emmanuel Macron won a second term Sunday over far-right challenger Marine Le Pen, who had pledged to dilute France’s ties with the European Union and NATO. Le Pen had also spoken out against EU sanctions on Russian energy and had faced scrutiny during the campaign over her previous friendliness with the Kremlin.

Since failing to capture Kyiv, the Russians have aimed to gain full control over the Donbas, where Moscow-backed separatists controlled some territory before the war.

For the Donbas offensive, Russia has reassembled troops who fought around Kyiv and in northern Ukraine. The British Ministry of Defense said Ukrainian forces had repelled numerous assaults in the past week and “inflicted significant cost on Russian forces.”