Marco Rubio says he will decide on 2016 White House run in 'due time'
Senator Marco Rubio speaks to the American Enterprise Institute (AFP)

Republican U.S. Senator Marco Rubio said on Wednesday he was still weighing whether to run for president or put his focus on his Senate re-election campaign.

Rubio, a Florida senator, is part of a crowded field of potential Republican 2016 contenders, including former Florida Governor Jeb Bush, New Jersey Governor Chris Christie and two- time presidential candidate Mitt Romney, a former governor of Massachusetts.

Bush, son of former President George H.W. Bush and brother of former President George W. Bush, and Romney have extensive experience in the private sector. Christie is a former attorney general. None have served in the U.S. Congress.

"I know I need to make a decision in due time if I want to be able to mount a credible campaign," the 43-year-old senator said.

Rubio said the foreign policy experience he gained from serving on relevant congressional panels would set him apart from the current and former governors during a White House bid.

Florida does not allow candidates to run concurrent congressional and presidential campaigns. Rubio, whose Senate term is up for re-election in 2016, told a breakfast hosted by the Christian Science Monitor that he would decide early enough to mount a viable White House campaign should he decide to run.

Moves by Bush to court high-profile Republican donors and an announcement by him in December that he was actively considering a run will make it harder for Rubio to raise money for a presidential bid of his own.

Rubio, who served in the Florida legislature while Bush was governor, would compete with many of the same donors in their home state.

Rubio said that Bush, with whom he is close, is a "very credible candidate" who could raise the amount of money necessary to run a presidential campaign. Though the two have been in contact, Rubio declined to say whether they had discussed their respective plans.

(Reporting By Amanda Becker)