South Carolina Sen. Lindsey Graham announced on Monday that he is dropping out of the Republican presidential primary race.

"Today, I'm suspending my campaign for president," Graham said in a YouTube video. "I want to thank everyone who has taken this journey with me. You have honored me with your support. I believe we have run a campaign you can be proud of. We put forth bold and practical solutions to big problems."

In the video, he stated the centerpiece of his campaign was securing the nation from terrorism and pushing for a strategy to defeat the Islamic State (ISIS). His hawkish foreign policy plan included sending 20,000 ground troops to Iraq and Syria, which was one of the most aggressive strategies among the presidential candidates.

"Four months ago at the very first debate, I said that any candidate that did not understand that we need more American troops on the ground in Iraq and Syria to defeat ISIL was not ready to be commander-in-chief. At that time, no one stepped forward to join me," the senator said in the video.

Throughout his campaign, the third-term senator also unleashed harsh attacks against GOP front-runner Donald Trump, calling him "a race-baiting, xenophobic, religious bigot."

"You know how you make America great again? You tell Donald Trump to go to hell," Graham said in the last GOP debate.

Earlier this year, Graham said the real estate mogul was "destroying the Republican chances to win an election" by using "hateful" anti-immigration rhetoric.

Despite his push for comprehensive immigration reform and an aggressive foreign policy, Graham failed to gain traction in the presidential race. National surveys conducted by ABC News and The Washington Post showed that he never received more than 1 percent of support from likely Republican voters. Meanwhile, he had earned just 1 percent of support from GOP voters in his home state, according to a recent CBS News/YouGov South Carolina poll.

Because of his low polling average, the 60-year-old congressman was prohibited from participating in the main stage GOP debates and consistently relegated to the undercard contests.