According to a Ukrainian government official, Ukrainian intelligence indicates Belarus’ “readiness to possibly participate directly” in the invasion of Ukraine, “in addition to allowing Russians to use their territory and cross the border.”

According to a second source close to the Ukrainian government, the Biden administration has informed the Ukrainian government that, in addition to Ukrainian intelligence, Belarus is preparing to join the Russian invasion.

The information raised new concerns within the Biden administration. According to a senior administration official, the White House is closely monitoring Belarus’s actions and is prepared to impose additional sanctions on the country. The US announced Monday that it was suspending operations at its embassy in Belarus, a sign of the region’s escalating turmoil.

As Russia’s unprovoked invasion of Ukraine enters its fifth day, talks between Russia and Ukraine began near the Belarussian border on Monday.

According to a senior Biden administration official, the White House is closely monitoring Belarus’s actions and is prepared to impose additional sanctions on the country amid reports that Belarusian forces may join Russia’s invasion of Ukraine.

“We’ve said that if Belarus continues to aid and abet Russia’s aggression in Ukraine, they will face consequences,” said a senior administration official. “Some of these measures have already been implemented. Those costs will continue to rise dramatically.” Last week, the US Treasury Department imposed sanctions on 24 Belarusians and entities.

In announcing the decision to suspend operations at the US Embassy in Belarus, US Secretary of State Antony Blinken cited the “unprovoked and unjustified attack by Russian military forces in Ukraine,” but provided no evidence of Belarusian military action. Non-emergency employees and family members will also be allowed to leave the US Embassy in Moscow, according to Blinken.

Belarus President Aleksander Lukashenko stated last week that Belarusian troops could participate in the invasion “if necessary.”

“Our troops are not taking part in this operation in any way. We’re not going to justify our participation or non-participation in this conflict here. I will say it again. Our troops are not present, but if necessary, if Belarus and Russia require them, they will be present “Lukashenko made the remarks on state news agency Belta’s YouTube channel.

Meanwhile, Ukrainian President Volodymyr Zelensky addressed Belarusians as “neighbors” on Sunday.

“Belarusians, this is also a referendum for you. You get to choose who you are and who you want to be. How would you appear in the eyes of your children? How you’d look at each other. In the eyes of your neighbor. And we live next door to you,” he stated. Zelensky’s office said Lukashenko called the Ukrainian president Sunday to discuss Monday’s meeting.

“Politicians have agreed that the Ukrainian delegation will meet with the Russian delegation without preconditions near the Pripyat River on the Ukrainian-Belarusian border,” Zelensky’s office said. “Aleksander Lukashenko has accepted responsibility for ensuring that all planes, helicopters, and missiles stationed on Belarusian territory remain on the ground throughout the Ukrainian delegation’s travel, meeting, and return.”

Belarus announced on Sunday that the country’s non-nuclear status had been renounced in a referendum that day. According to the Belarus Central Elections Commission, 78.63 percent of the eligible voting population participated in the referendum on Sunday, with 65.16 percent voting in favor of approving a new constitution that will end the country’s non-nuclear status and allow Lukashenko to run for two more terms in office. The new constitution could theoretically allow Russia to reintroduce nuclear weapons into Belarus for the first time since the Soviet Union’s demise, when Belarus surrendered its stockpile and declared itself a nuclear-free zone.

According to Lukashenko’s office, the amendments and additions to the constitution approved in the referendum on Sunday will take effect in 10 days.