Lindsey Graham says he is running for White House
Senator Lindsey Graham, the Republican foreign policy hawk, has confirmed that he will run for US president in 2016.
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.
Analysis - Anthony Zurcher, BBC News, Washington
Lindsey Graham tried to be coy about whether he was going to run for president, but his decision is clear - he's in. That makes four members of the US Senate - 9% of all Republican senators in office in 2014 - now running.
A foreign policy hawk in the mould of Senator John McCain of Arizona, he is likely to make national security the central theme of his campaign. If polls are to be trusted, that may play well with Republican audiences.
He is still a long-shot, however, given that his past efforts at co-operation with Democrats and support of sweeping immigration reform put him out of step with many Republican primary voters.
The mere fact that he's in a position to run for president now, however - given that just a few years ago he was seen as a prime target for a grassroots Tea Party primary challenger - is an impressive political achievement.
When asked by CBS whether he thought the Republican field was weak, he revealed his intention to run himself.
"I'm running because of what you see on television, I'm running because I think the world is falling apart, I've been more right than wrong on foreign policy," he said.
"It's not the fault of others, or their lack of this or that that makes me want to run, it's my ability in my own mind to be a good commander-in-chief and to make Washington work."
2016 runners and riders
- An early (undeclared) Republican frontrunner is Jeb Bush
- Hillary Clinton will have learnt much from her failed campaign of 2008
- New Jersey Governor Chris Christie could battle Jeb Bush for the party's centre ground
- Texas Senator Ted Cruz is a darling of the Tea Party
- Libertarian Rand Paul has his supporters - and enemies - among Republicans
- Maryland Governor Martin O'Malley has already begun an undeclared Democratic campaign