Pentagon says Russian troop movements 'not a real withdrawal'; U.S. warns of global food insecurity

This has been CNBC's live blog covering Tuesday's updates on the war in Ukraine. [Follow the latest updates here.]

Russia claimed it would reduce its attacks on Ukraine as delegates from the two countries met for their latest face-to-face peace talks in Istanbul.

Moscow said it would cut back its military activity near Ukraine's capital of Kyiv and the northern city of Chernihiv, though Russia has not followed through on similar pledges in the past.

Ukrainian officials have pushed for a cease-fire agreement and a resolution to the humanitarian crisis sparked by Moscow's invasion. After the day's talks ended, an official from Ukraine's delegation called for an international security guarantee similar to NATO's Article 5.

'Nothing has changed': Russia is just buying time with negotiations, says think tank

It's 'very, very unlikely' that the Russian military will overthrow Putin, says think tank
'Very, very unlikely' that the Russian military will overthrow Putin: Think tank

Russia is trying to buy more time through negotiations with Ukraine, according to Melinda Haring of the Atlantic Council.

"It is an attempt for the Russians to buy more time so that they can come back in, regroup and come back stronger," said Haring, who is deputy director of the Atlantic Council's Eurasia Center.

Moscow said overnight that it will scale back its military activity near the Ukrainian capital of Kyiv and the northern city of Chernihiv, but the Pentagon has cautioned it's not a retreat. Russia previously did not followed through with similar pledges.

"Nothing has changed today, that's the important point," Haring added.

"The bottom line is that Ukraine has to continue to fight, and fight very valiantly, and inflict major costs on Russia until Russia is ready to actually engage in real negotiations," The West will also need to continue to send defensive material to Ukraine, she added.

It will take "many more weeks and many more months" until the Russians will be willing to really negotiate, she said.

— Chelsea Ong

Russia's announcement is a 'distraction,' says professor

Russia's announcement that it is pulling its troops back from