Former U.S. Sen. Marco Rubio of Florida has officially been confirmed as the next U.S. secretary of state. The Senate confirmed him by a vote of 99-0 just hours after President Donald Trump was inaugurated."He will 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," Trump said at the time of Rubio's nomination.RELATED STORY | Rubio, Bondi among Trump nominees questioned by senatorsAlthough Rubio, 53, has been a vocal supporter of Trump in recent years, that wasnt always the case. The two frequently sparred while competing for the 2016 Republican presidential nomination.However, they seemed to mend fences once President Trump secured the Republican Party nomination and later the presidency. Rubio, who is now the highest ranking official in President Trump's cabinet, will be tasked with implementing his foreign policy agenda, negotiating international agreement, and overseeing diplomatic relations abroad.RELATED STORY | Pete Hegseth, Trump's Defense Department pick, faces fiery confirmation hearingDuring his Senate confirmation hearings, Rubio faced questions over whether the U.S. will continue to back Ukraine, and how the Trump administration will deal with adversaries such as China, Russia and North Korea. He told lawmakers that in order to bring an end to the war in Ukraine, the U.S., Russia and Ukraine would all have to make concessions."It's also important that there be some balance on both sides. In essence, it will be difficult to achieve this objective of a ceasefire and ultimately a peace settlement, unless both sides have leverage," he said.