In a pre-Christmas visit in December 2019, fresh from his election victory, Boris Johnson visited the base to serve turkey and Yorkshire puddings to troops from the Queen’s Royal Hussars.

Back home on Tuesday, a poll of Tory members by the blog Conservative Home showed Ms Truss remains the most popular Cabinet minister, with a net satisfaction rating of 82.3 per cent.

Her visit to the Baltics continued as she joined the foreign ministers of other Nato countries in Riga, Latvia, for a summit.

She said that Nato was not provoking Russia into military action in Ukraine and any invasion by Vladimir Putin would be a “strategic mistake”.

Ms Truss rejected claims that a military build-up of Russian forces on the Ukrainian border was a response to provocation by Nato countries, and pledged to “stand with our fellow democracies” against “malign” activity in the region.

“We have seen this playbook from the Kremlin before when Russia falsely claimed its illegal annexation of Crimea was a response to Nato aggression,” she said.

“Nato is an alliance forged on the principle of defence, not provocation. Any suggestion that Nato is provoking the Russians is clearly false.”

She warned Mr Putin not to “undermine the freedom and democracy that our partners enjoy” by invading Ukraine, suggesting such a move would be a “strategic mistake”.

“We will support Ukraine and stability in the western Balkans, to safeguard their security and build their economic resilience,” she said.

The Foreign, Commonwealth and Development Office said Ms Truss will use the summit in Riga to call for the alliance to present a united front in standing up to Moscow while also keeping open channels of communication with the Kremlin.

Ukraine is not a member of Nato, and the alliance has previously suggested that it would not intervene militarily if Mr Putin was to invade.

On Tuesday Richard Moore, the chief of MI6, said Russia was an “acute threat” to the UK.

“From time to time we get sort of crises around Ukraine as we worry about build-up of troops and what President Putin’s intentions might be,” he said.

“It bears very careful watching and it bears very careful signalling to the Russians about the price that they would have to pay if they intervened, as they did in 2014,” he told the BBC.