President Joe Biden and a key U.S. ally have both rejected the idea of using their respective country’s troops to rein in Russia, as tens of thousands of President Vladimir Putin‘s troops amass at the country’s border with Ukraine.

British Defense Secretary Ben Wallace appeared to rule out deploying troops to Ukraine in order to defend the country if Russia invades in remarks to The Spectator magazine.

He said that it was “highly unlikely” NATO troops would be sent to Ukraine in the event of invasion, which U.S. intelligence suggest could potentially take place next month.

President Joe Biden has said on December 8 that his administration has not been considering a unilateral deployment of U.S. troops to the region, but he seemed to leave open the possibility of action by NATO countries.

The U.K. is a NATO member and a key, long-term U.S. ally, making its government’s position on troops potentially crucial.

In comments published by The Times ahead of The Spectator report, Wallace said that Ukraine “is not a member of NATO so it is highly unlikely that anyone is going to send troops into Ukraine to challenge Russia.”

Members of NATO are obliged by treaty to come each others’ defense if they are attacked, but Ukraine is not a party to NATO.

“We shouldn’t kid people we would. The Ukrainians are aware of that,” Wallace said. ”

Asked if Ukraine was on its own, he replied: “We can all help with capacity building but to some extent Ukraine is not in NATO and that is why we are doing the best diplomatically to say to Putin don’t do this.”

Speaking to reporters at the White House on December 8, President Biden said: “We have a moral obligation and a legal obligation to our NATO Allies, if they were to attack under Article Five. It’s a sacred obligation,” Biden said, explaining the U.S. did not have that obligation to Ukraine.

“But it would depend upon what the rest of the NATO countries are willing to do as well,” the president said. “But the idea the United States is going to unilaterally use force to confront Russia from invading Ukraine is not on…in the cards right now.”

Ukrainian servicemen walk in a trench on their position on the front line with Russia-backed separatists near the small town of Svitlodarsk, in Donetsk region, on December 18, 2021. Russian troops are continuing to amass along the Ukrainian border.

Biden warned of “severe consequences” if Russia invades Ukraine and the administration has been working to find a diplomatic solution while also reportedly working on potential economic sanctions. The president addressed the issue with Putin directly in a virtual meeting last week.

While Russian officials have repeatedly dismissed the idea that the country is poised to invade, some 70,000 Russian troops are now amassed at the Ukrainian border, according to U.S. intelligence.

This reportedly includes 50 Battalion Tactical Groups (BTGs) that combine a number of functions, including artillery, anti-tank weapons and reconnaissance. Six more BTGs are believed to be en route

U.S. intelligence previously estimated that Russia could have as many 175,000 troops on the border ahead of a potential invasion in January.

This composite image shows U.K. Defense Secretary Ben Wallace and U.S. President Joe Biden. Wallace has said NATO troops deploying to protect Ukraine is unlikely.

This article was written by Darragh Roche and originally published by Newsweek.