The Chief diplomats of the United States and Russia are to meet in Sweden on Thursday as tensions soar after Washington expressed concern about Russia's military buildup near Ukraine and warned of high-impact sanctions.   

Earlier, at a NATO meeting in Latvia's capital Riga, US Secretary of State Antony Blinken showed deeply concerned by evidence that Russia has made plans for significant aggressive moves against Ukraine.

He said diplomacy is the only responsible way to resolve this potential crisis" but warned there would be "far-reaching and long-lasting consequences" for Moscow if it pushed ahead with any aggression.