WASHINGTON - South Carolina Senator Lindsey Graham, a noted defense hawk, announced on Monday his presidential bid with national security as a pivotal issue.

US Republican presidential candidate U.S. Senator Lindsey Graham talks with supporters after announcing his campaign for the 2016 Republican presidential nomination in Central, South Carolina June 1, 2015.  [Photo/Agencies]

"I've got one simple message," Graham told supporters in his hometown during a rally. "I have more experience with our national security than any other candidate in this race. That includes you, Hillary."

Graham, 59-year-old retired Air Force colonel, entered the Republican field at a time when fierce battle over national security rages in the Senate. Though falling short of naming his Republican colleague Senator Rand Paul, also a presidential candidate who had become a vocal opponent of the anti-terror Patriot Act, Graham made it clear his opposition to the expiration of surveillance programs and support for a more active military intervention overseas.

"The Obama administration and some of my colleagues in Congress have substituted wishful thinking for sound national security strategy," Graham told supporters. "I'm afraid some Americans have grown tired of fighting them, (but) the radical Islamists are not tired of fighting you. In partnership with others, we must take the fight to them, building lines of defenses over there, so they can't come here."

Before his Monday announcement, Graham said recently that there was no avoiding the reality that more Americans would have to fight and die to defend the country.

Graham was the ninth Republican candidate to formally announce 2016 White House bid and his national supporting rate was about 2 percent or less.