5 in a race where he beat Vice President Kamala Harris as the Democratic nominee, has repeatedly promised to end the war "in 24 hours.”Though Trump hasn't yet elaborated on his plan, it is expected to involve Ukraine ceding land to Russia or agreeing to a ceasefire and freeze of front-line positions, with Russia holding on to some 20 percent of Ukrainian territory.If appointed, Rubio would be the U.S.' top diplomat, at the forefront of any peace negotiations between Kyiv and Moscow.Who is Marco Rubio?Rubio, 53, is a Republican senator from Florida. The son of Cuban immigrants, he would be the first Latino U.S. secretary of state.How important is Trump’s choice of secretary of state for Ukraine?Very. The Secretary of State job is the U.S.