Ukraine war live updates: Pentagon chief looks to convince Ukraine of ongoing support; Putin attends rally in Moscow

This is CNBC's live blog tracking developments on the war in Ukraine. See below for the latest updates. 

U.S. Defense Secretary Lloyd Austin will on Tuesday try to convince Ukraine and other European allies that President Joe Biden's administration is still committed to supporting Kyiv, even as Washington's funds run too low for it to be able to do so.

Austin will be leading the Ukraine defense contact group meeting at the Ramstein Air Base in Germany on Tuesday, with representatives from Ukraine and around 50 of its allies attending.

In other news, Russian President Vladimir Putin briefly attended an open-air rally in Moscow on Monday evening at which he told the crowd that the annexation of Crimea and other regions in Ukraine had been difficult but worthwhile.

The rally and concert in Red Square marked the 10th anniversary of Russia's annexation of Crimea from Ukraine. The annexation was a precursor to a simmering conflict between pro-Russian separatists and Ukraine's armed forces in eastern Ukraine since 2014, and Russia's wholesale invasion of Ukraine in 2022.

Russian authorities in the Belgorod region are to evacuate around 9,000 children from the region, which borders Ukraine, because of repeated shelling by Ukraine's armed forces, the governor said Tuesday.

“Today we are resettling a large number of villages," Governor Vyacheslav Gladkov said at a United Russia party meeting Tuesday, news agency Tass reported.

"We are now planning to remove about 9,000 children from Belgorod" and several districts in the wider region, he said.

The governor said 16 people were killed and 98 injured because of shelling in the Belgorod region over the past week.

CNBC was unable to immediately verify the claim. Belgorod has been a