US President Joe Biden said Wednesday that he expects Russian President Vladimir Putin to order an invasion of Ukraine, and warned that “a disaster” awaits Russia if that happened, CNBC reported.

Biden’s remarks came after intelligence agencies warned such an attack could happen within a month.

“My guess is he will move in, he has to do something,” Biden said when asked about the more than 100,000 Russian troops positioned along Ukraine’s border.

“It is going to be a disaster for Russia if they further invade Ukraine. Our allies and partners are ready to impose a severe cost on Russia and the Russian economy,” Biden said during his second solo news conference since he took office.

“And I think he’ll regret having done it,” Biden said of a possible invasion.

When asked about presenting a united front against Russia, Biden downplayed concerns that Washington and European allies won’t be able to agree on a joint sanctions package should Moscow pursue aggression.

“He’s never seen sanctions like the ones I promised,” the US president said of Putin, adding that Moscow will “pay a stiff price immediately, near term, medium-term and long term.”