Donald Trump is expected to tap US Senator Marco Rubio to be his secretary of state, sources said, putting the Florida-born politician on track to be the first Latino to serve as America’s top diplomat once the Republican president-elect takes office in January.Rubio was arguably the most hawkish option on Trump’s shortlist for secretary of state, and he has in past years advocated for a muscular foreign policy with respect to America’s geopolitical foes, including China, Iran and Cuba.Over the last several years he has softened some of his stances to align more closely with Trump’s views. The president-elect accuses past US presidents of leading America into costly and futile wars and has pushed for a more restrained foreign policy.While the famously mercurial Trump could always change his mind at the last minute, he appeared to have settled on his pick as of Monday, according to the sources, who requested anonymity to discuss private conversations. The apparent Rubio selection has generated concern among some Trump allies who see the Florida senator as having a world view and establishment credentials at odds with the more isolationist stance favoured by the Republican hard right.Some cautioned on the social media site X that the choice of Rubio had not been finalised, although it was unclear where their information was coming from.Caroline Wren, a pro-Trump fundraiser, mocked Rubio, comparing him unfavourably to former ambassador to Germany Richard Grenell, who was also in the running to be secretary of state.“Why would we have wanted someone totally loyal like Ric Grenell when we can have a Senator who is ‘totally owned by lobbyists’ and a ‘lightweight with the worst voting record in the Senate’?” Wren posted on X, referring to Trump’s own past statements about Rubio.Representatives for Trump and Rubio did not immediately respond to requests for comment. Neither Trump nor Rubio has spoken publicly about the matter.The new administration will confront a world more volatile and dangerous than it was when Trump took office in 2017, with wars raging in Ukraine and the Middle East and with China aligning itself more closely with US foes Russia and Iran.The Ukraine crisis will be high on Rubio’s agenda.Rubio, 53, has said in recent interviews that Ukraine needs to seek a negotiated settlement with Russia rather than focus on regaining all territory that Russia has taken in the last decade. He was also one of 15 Republican senators to vote against a $95bn military aid package for Ukraine, Israel and other US partners, passed in April.