Russia's top diplomat warned Ukraine against provoking World War III and said the threat of a nuclear conflict should not be underestimated, as his country unleashed attacks against rail and fuel installations far away.

The British Defense Ministry said Tuesday that Russian forces had taken the Ukrainian city of Kreminna in the Lukansk region after days of street-to-street fighting.

The British military said in a statement that the city of Kreminna has reportedly fallen and heavy fighting is reported south of Izium as Russian forces attempt to advance towards the cities of Sloviansk and Kramatorsk from the north and east. It didn't say how it knew the city had fallen. The Ukrainian government didn't comment immediately.

The U.S. has been rushing more weaponry to Ukraine and said the assistance from Western allies is making a difference in the 2-month-old war.

The U.S. diplomats in Ukraine are sending a signal to Russia.

Russia is failing. The U.S. secretary of state and the secretary of defense made a bold visit to Kyiv to meet with the president.

A $165 million sale of non-U.S. ammo was approved by the US, which will provide more than $300 million in financing to buy more supplies.

Lloyd Austin said the U.S. wants to see Ukraine remain a democratic country, but also wants Russia to be weakened so it can't do things like invade the country.

Austin said that the goal of American military aid was to help Ukraine win and to defend its NATO neighbors against Russian threats.

Lavrov’s warning to Ukraine

In an apparent response to Austin, Russian Foreign Minister Sergei Lavrov said that Russia has a feeling that the West wants to exhaust the Russian army and the Russian military industrial war complex. This is not a reality.

Weapons supplied by Western countries will be a legitimate target for Russian forces.

The Ukrainian leaders were accused of provoking Russia by asking NATO to get involved in the conflict. He said that NATO entered into a war with Russia through proxies. According to a transcript on the Russian Foreign Ministry website, NATO forces are pouring oil on the fire.

He said in a Russian television interview that everyone is saying that World War III can't happen.

A foreign fighter is on the front line.

When the risks of a nuclear confrontation are more significant, he wouldn't want to see them inflated.

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

Ukrainian Foreign Minister Dmytro Kuleba said that Russia lost its last hope to scare the world off supporting Ukraine. There is a danger of WWIII. This only means that Moscow is losing in Ukraine.

Russia’s new military objectives in Ukraine

Russia's goal when it invaded Ukraine was to seize the capital. The Ukrainians forced Putin's troops to retreat.

The goal of Moscow is to take the mostly Russian-speaking industrial region of eastern Ukraine. Russia has yet to mount an all-out ground offensive or make any major breakthrough in the campaign.

Russian warplanes and missiles struck far behind the front lines to try to stop Ukrainian supply efforts on Monday.

Oleksandr Kamyshin, head of Ukraine's state railway, said that five railroad stations were hit and one worker was killed. The western city near the Polish border has been swelled by Ukrainians fleeing the violence elsewhere.

Russian strikes killed at least five people in the central Vynnytsia region.

The Defense Ministry spokesman said that Russia destroyed an oil refinery and fuel depot in central Ukraine. Russian warplanes destroyed 56 Ukrainian targets.

Philip Breedlove, a retired U.S. general who was NATO's top commander, said the strikes on fuel depots are meant to deplete key Ukrainian war resources. Strikes against rail targets are an effort to disrupt supply lines.

Ukrainians are speaking up against rape.

The illegitimate reason is they know people are trying to leave the country, and this is just another terrorist tactic to make them not have faith and confidence in traveling on the rails.

The professor of strategic studies at the University of St. Andrew's said that the war is settled into a campaign of small battlefield losses and gains.

The two sides weaken each other every day, he said.

The Ministry of State Security in Transnistria was hit by several explosions believed to have been caused by rocket-propelled grenades. There were no reports of injuries or a claim of responsibility. A strip of land with over 470,000 people is called Transnistria. There are about 1,500 Russian troops there.

The aim of today's incident is to create pretexts for straining the security situation in the Transnistrian region.

A Russian military commander said last week that the Kremlin wants to open the way to Transnistria.

Siege continues at Mariupol

Russian forces are being held in a steel plant in Mariupol by an estimated 2,000 Ukrainian troops, preventing them from joining the offensive elsewhere in the Donbas. Russian forces launched new airstrikes on the Azovstal plant to try to get the holdouts.

The civilians were said to be taking shelter at the steelworks.

There is a new mass grave north of Mariupol, according to the city council and mayor. The number of victims was being estimated, according to the Mayor. There were at least three new mass graves discovered near Mariupol in the last week.

Mariupol has been ravaged by street fighting over the past two months. Russia's capture of the city would deprive Ukraine of a vital port and give Moscow a land corridor to the peninsula.

Five Ukrainian photographers document the war.

Zelenskyy said in his video address that Ukraine was continuing its resistance to make the occupiers stay in our land even more intolerable.

Britain believes that 15,000 Russian troops have been killed in Ukraine. 25% of the Russian combat units sent to Ukraine have been rendered not combat effective, according to Defense Secretary Ben Wallace.

Ukrainian officials have said that between 2,500 and 3000 Ukrainian troops have been killed.

Gambrell was reported from Lviv, Ukraine. The report was contributed to by Associated Press journalist Yuras Karmanau and AP staff around the world.

We can be reached at letters@time.com.