Joe Biden has said he will consider personal sanctions against Vladimir Putin if Russia invades Ukraine, as western leaders step up military preparations and make plans to shield Europe from Russian gas being cut off, writes The Guardian.

The rare sanctions threat came as NATO placed forces on standby and reinforced eastern Europe with more ships and fighter jets in response to Russia’s troop buildup near its border with Ukraine.

If Russia attacked, Biden said, it would be the “largest invasion since world war two” and would “change the world”. The president said he would consider adding direct sanctions on Putin to a raft of measures being drawn up.

“Yes. I would see that”, Biden said when asked by reporters in Washington about targeting Putin, whom opponents have long accused of holding gigantic secret wealth.

A senior US official laid out economic sanctions “with massive consequences” going far beyond previous measures implemented in 2014 after Russia invaded Ukraine’s Crimea region.