The president-elect said Senator Rubio would be “a strong advocate for our nation, a true friend to our allies and a fearless warrior who will never back down to our adversaries.”
The three-term senator from Florida viciously criticized Donald J. Trump during the 2016 campaign but has since ingratiated himself and become a foreign policy adviser to Mr. Trump.
The president-elect appears to have settled on the Florida senator, who has taken hard-line positions on China, Iran and Venezuela, to be the nation’s top diplomat.