Washington ? Sen. Bob Graham of Florida said Thursday that he would undergo heart surgery in early February, postponing announcement of a bid for the Democratic presidential nomination.

Graham told reporters in his office that he had made up his mind to run and was planning to announce his candidacy Feb. 3 in Tallahassee, Fla. Now, Graham said, he will have surgery to replace a faulty aortic valve that same week.

“While I am a fire horse ready to get in harness, out with the people of the early states, I recognize I am going to have to stay in the barn longer than I anticipated,” he said. Graham said he had been eager to enter the race because of his concerns about the Bush administration’s handling of the war on terrorism and the economy.

“The war on terrorism is imminently winnable,” Graham said, “but we are about to lose that war because we have allowed ourselves to be diverted to not meaningless activities but activities that are of a lower priority.”

The 66-year-old senator said he would wait a month to six weeks after surgery to reassess whether he should run.

Florida’s senior senator was told of the need for surgery after a catheterization that was part of medical tests he had conducted to find out if he should proceed with a presidential run.