Secretary of State Marco Rubio speaks to the press before boarding his plane at Homestead Air Reserve Base, Thursday. Rubio is traveling to a NATO foreign ministers meeting in Sweden. [AP]

Secretary of State Marco Rubio is on his latest mission to assuage nervous US allies in Europe about the Trump administration’s intentions with NATO or at least put a friendlier face on whipsawing changes and uncertainty about American troop reductions.

Rubio will attend a NATO foreign ministers’ meeting in Sweden on Friday – the same day senior Pentagon officials are expected to brief the 32-nation alliance on plans for the US military’s commitment to European defense at the alliance’s headquarters in Brussels.

The meeting of diplomats, which precedes a NATO leaders’ summit in Turkey in July, comes amid great uncertainty over how the war in Iran will play out and whether stalled US efforts to broker an end to the Russia-Ukraine conflict will resume. Resentment also still simmers on the continent over President Donald Trump’s criticism of allies and his interest in taking over Greenland, a territory of NATO ally Denmark.

Rubio has often been called on to offer a calmer, less antagonistic presence from the Trump administration at meetings like these. He has been dispatched on several such missions this year, including the Munich Security Conference in February and, more recently, to Italy, where he met with Italian officials and Pope Leo XIV after Trump criticized the American pontiff for his stances on crime and the Iran war.