Republican Lindsey Graham quits 2016 race
Republican presidential candidate Lindsey Graham has said he is dropping out of the race for his party's nomination.
"Today, I'm suspending my campaign for president," the South Carolina senator said in a video posted on YouTube.
The 60-year-old said it had been "a campaign we can be proud of" that was focused on US security.
The senator has performed well in the second-tier televised debates but failed to make an impact in the polls.
When he launched his campaign earlier in the year, the foreign policy hawk emphasised his national security credentials, and he did so again when quitting the race on Monday.
He said the centrepiece of his campaign had been "securing our nation" and he had tried to "turn back the tide of isolationism that has been rising in the Republican Party".
In this he had made enormous progress, he said, because some fellow Republicans had come round to his thinking that more US troops were needed on the ground in Syria and Iraq to fight Islamic State.
Analysis - Gary O'Donoghue, BBC Washington correspondent
Lindsey Graham was one of the most hawkish candidates in the crowded Republican field, favouring a substantial injection of American boots on the ground to combat the militants of Islamic State.
Indeed, his whole presidential pitch turned on his approach to foreign affairs and security, from his place on the Senate Armed Services Committee, where he serves under the chairmanship of his friend and mentor, Senator John McCain.
But despite regular appearances on cable TV and political talk shows, he failed to break out of the group of candidates polling in low single-digit percentages.
In particular, he struggled to win substantial Republican backing after previous attempts to work on immigration reform with Democrats.
When I saw him speak at a Rotarian event in new Hampshire 10 days ago, he was full of self-deprecation, simultaneously spitting blood about the Republican frontrunner Donald Trump, whom he described as a school-yard bully.
We can safely say Senator Graham will not be throwing his modest weight behind Trump for president.
His departure leaves 12 main Republicans left in the contest, six weeks before the battle for each party's nomination begins in Iowa.