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US President Joe Biden has expressed scepticism on a promise made by Moscow that Russia would reduce its military forces around Kyiv and in the north of Ukraine.
"We'll see. I don't read anything into it until I see what their actions are," Mr Biden told reporters during a joint statement with Singapore Prime Minister Lee Hsien Loong on Tuesday when pressed on the matter.
"We'll see if they follow through on what they're suggesting."
Russia has started moving very small numbers of troops away from positions around Ukraine's capital Kyiv, the Pentagon said on Tuesday, adding it was more of a repositioning than a retreat or a withdrawal from the war.
"Has there been some movement by some Russian units away from Kyiv in the last day or so? Yes, we think so. Small numbers," Pentagon spokesman John Kirby told a news briefing.
"But we believe that this is a repositioning, not a real withdrawal, and that we all should be prepared to watch for a major offensive against other areas of Ukraine."
Mr Kirby said the threat to Kyiv is not over, but any redeployment from the capital marks a major Russian setback.
"They failed to take Kiev, and we believe that Kiev was a key objective for them," he said.
Russia's deputy defence minister earlier on Tuesday said Moscow would drastically cut its military activity focused on Kyiv and Chernihiv in Ukraine after talks between Russian and Ukrainian negotiating teams in Istanbul.
Deputy Defence Minister Alexander Fomin said the promise to scale back fighting around Kyiv was meant to create mutual trust and the necessary conditions for more talks to take place.
Russia set to sharply reduce military activity around Kyiv and Chernihiv
Mr Biden on Tuesday spoke with British Prime Minister Boris Johnson and other western leaders to reaffirm their commitment to supporting Ukraine.
In a call with other members of “the Quint” — France, Germany and Italy — they stressed the need to “reshape the international energy architecture” and reduce dependence on Russian hydrocarbons, Downing Street said.
“[Russian President Vladimir] Putin is twisting the knife in the open wound of Ukraine in an attempt to force the country and its allies to capitulate,” a spokesman for No 10 said.
“[The Quint leaders] agreed there could be no relaxation of western resolve until the horror inflicted on Ukraine has ended.”
In a statement, the White House said the leaders affirmed their determination in continuing to punish Russia for its invasion, as well as reviewing efforts to provide humanitarian assistance to those inside of Ukraine and those seeking refuge in other countries.
Agencies contributed to this report.