Lindsey Graham says he is running for White House
The senator from South Carolina told CBS This Morning that he would make an official announcement on 1 June in his home town of Central.
But when asked why he was considering it, he said "I'm running" because "the world is falling apart" and he would make the best commander-in-chief.
He becomes the seventh leading Republican to join a crowded field.
Mr Graham has been a fierce critic of President Barack Obama's foreign policy, particularly in the Middle East.
He wants US ground troops to be sent into Iraq and Syria to combat Islamic State, to prevent terror attacks in the US.
