Russia-Ukraine updates: Putin suspends key US-Russia nuclear treaty in speech denouncing West

More than 100,000 Russian soldiers battling in Ukraine have either been killed, reported missing or defected since the war began in February, according to estimates released Tuesday by British Defense Secretary Ben Wallace.

Marking the 300th day of the war, Wallace provided the update on Russia's war losses to the House of Commons in London. He also estimated that 4,500 Russian armored vehicles have been destroyed as well as 140 Russian helicopters and fixed wing aircraft.

The estimated losses by Russian forces are similar to what Ukrainian officials have released.

Wallace said the number of missions to Ukraine by the Russian Air Force have drastically declined from 300 a day in March to currently tens of missions per day.

He described Russia’s once powerful Black Sea fleet as "little more than a coastal defense flotilla."

In March, Russia occupied about 27% of Ukrainian territory, Wallace said. Since then, Ukraine liberated around 54% of the territory that has been taken since February.

He said Russia now controls roughly 18% of internationally recognized areas of Ukraine.

The Kremlin has yet to respond to Wallace's battlefield estimates.

Russia has failed to achieve any strategic objectives, Wallace said, adding that not one Russian operational commander who was in place at the start of the Russian invasion Feb. 24 remains.

Wallace also spoke about a deal between the Kremlin and Iran to supply Russia with more than 300 kamikaze drones.

"Iran has become one of Russia's top military backers," Wallace said.

He said that in exchange, Russia intends to provide Iran with advanced military components, undermining international security, particularly in the Middle East.

"We must expose that deal," Wallace said.

Ukrainian President Volodymyr Zelenskyy on Tuesday made an unannounced trip to Bakhmut, Donetsk Oblast, posing for pictures with soldiers and handing out awards, as he inspected the front lines.

Zelenskyy said Monday that Bakhmut remains the "hottest point" out of the entire 1,300-kilometer front line as Russian forces relentlessly try to break Ukraine's defenses in the city.

-ABC News' Guy Davies

Ukrainian President Volodymyr Zelenskyy provided an update on Monday's strike by Russian forces, citing that the blasts came from a "new batch" of drones.

Zelenskyy, however, said in a statement that most of the Iranian Shaheds drones "fell short of their intended targets,"

"[Thirty] Shaheds were shot down - not bad," he said in a statement.

Zelenskyy appealed to the leaders of the Northern European countries with a request to provide more weapons, shells, and new defense capabilities.

-ABC News' Will Gretsky

Russian President Vladimir Putin and Belarus leader Alexander Lukashenko have concluded their talks in Belarus’ capital Minsk, hailing their countries’ close relationship, but giving few details of any agreements they reached.

The two leaders gave a joint press conference following their talks in front of their top officials, including Putin’s defense minister, Sergey Shoigu, and foreign minister, Sergey Lavrov.

Putin and Lukashenko gave little indication they had agreed for Belarus to play a greater role in Russia’s war in Ukraine. But Putin said the two sides had agreed to continue joint military exercises and were developing a shared military doctrine.

Lukashenko and Putin both said they agreed Russia would train Belarusian pilots to fly nuclear-capable bombers. The Kremlin and Lukashenko have previously hinted at the possibility Russia would deploy nuclear weapons to Belarus -- an apparent threat to Europe.

"I consider it possible to continue the implementation of the proposal of the President of Belarus to train the crews of combat aircraft of the Belarusian army, which have already been converted for the possible use of air-launched ammunition with a special warhead," Putin said.

Putin also denied that Russia had any intention of “swallowing” anyone up, referring to speculation that Russia has pressured Lukashenko to sacrifice Belarus’ political and economic independence to Moscow in return for its help in propping up his dictatorship.

-ABC News' Patrick Reevell