WASHINGTON: US President Joe Biden suggested Vladimir Putin's struggle in Ukraine after 10 months of war and thousands of lives lost had prompted the Russian president to offer a 36-hour truce, saying, "I think he's trying to find some oxygen".

The Kremlin said Putin had ordered a ceasefire from midday on Friday after a call for a Christmas truce by Patriarch Kirill of Moscow, head of the Russian Orthodox Church.

Ukraine spurned the ceasefire offer over Orthodox Christmas, saying there would be no truce until Russia withdraws its invading forces from occupied land.

Asked about the proposed truce, Biden told reporters at the White House: "I'm reluctant to respond to anything that Putin says. I found it interesting that he was willing to bomb hospitals and nurseries and churches ... on the 25th and New Year's. I mean, I think he's trying to find some oxygen."

Putin's ceasefire would begin on Jan 6, when many Orthodox Christians, including those living in Russia and Ukraine, celebrate Christmas. It would be the first major truce of the more than 10-month-old war that has claimed tens of thousands of lives and devastated large swaths of Ukraine.

(Source Reuters)