By GEIR MOULSON
BERLIN (AP) — Diplomatic efforts to head off what U.S. officials have warned could be an imminent Russian attack on Ukraine have entered a new and dizzying round. Russia’s top diplomat advised President Vladimir Putin to continue talks and Germany’s chancellor met the Ukrainian president. British Prime Minister Boris Johnson says Europe is “on the edge of a precipice,” but there’s still time for Putin to “step back.” The U.S. announced it is closing its embassy in Ukraine, and told Americans in neighboring Belarus to leave the country immediately. Secretary of State Antony Blinken also says the U.S. will offer a loan guarantee of up to $1 billion to help Ukraine bolster its economic stability.