US President Joe Biden spoke on Tuesday with Russian President VladimirPutin for the first time over the phone since his inauguration.

A statement issued by the White House confirmed that Biden reaffirmed thesupport of the US for the sovereignty of Ukraine in the face of Moscow’ssupport for separatists in the east of the country and its continuedoccupation of Crimea.

The two leaders also discussed willingness to extend New START for fiveyears, agreeing to have their teams work urgently to complete the extensionby February 5.

Signed in 2010, the New START (Strategic Arms Reduction Treaty) is acornerstone of global arms control.

It limits the number of strategic nuclear warheads deployed by the UnitedStates and Russia to 1,550 each as well as the number of land- andsubmarine-based missiles and bombers that deliver them.

The statement read that President Biden made clear that the US will “actfirmly” in defense of its national interests in response to actions byRussia that harm US or its allies.