U.S. President Joe Biden is scheduled to speak to Ukraine’s president this weekend after warning Russia not to invade Ukraine. Biden will “reaffirm U.S. support for Ukraine’s sovereignty and territorial integrity, discuss Russia’s military build-up on Ukraine’s borders, and review preparations for upcoming diplomatic engagements to help de-escalate the situation in the region,” according to a White House official. Volodymyr Zelensky, the president of Ukraine, said in a statement that he looked forward to speaking to Biden “to coordinate our steps for the sake of peace in Ukraine and security in Europe.” Biden last spoke with Zelensky last month, when he promised no decisions or discussions would be made “about Ukraine without Ukraine.” Biden talked with Russian President Vladimir Putin this week for nearly an hour. According to the White House, Biden attempted to de-escalate the tensions between Russia and Ukraine, which was once part of the Soviet Union. “I …