SUN CITY CENTER, Fla. -- Like a pitchman promoting the final days of a big sale, President Bush on Tuesday urged more Medicare recipients to sign up for the new prescription drug benefit before Monday's enrollment deadline, and he rejected calls to extend it.

In a tour of the state with the highest percentage of senior citizens, Bush got thanks from some who said the benefit will save them money. But he also heard some complaints from people concerned about problems they have experienced, and at least two people asked him in a public forum to extend the impending enrollment deadline.

Those who don't sign up by May 15 will have to pay a penalty to enroll, although Bush repeatedly pointed out that there are exceptions for the poor. Many lawmakers want to extend the deadline, but Bush has opposed those calls.

"Deadlines are important," Bush said. "Deadlines help people understand there is finality and people have to get after it."

Bush's promotional tour of three Florida cities Tuesday and Wednesday was part of more than 1,000 events the government has staged nationwide this week as part of a final push to get people to sign up for the prescription drug benefit.

He stopped by Broward Community College, where government officials set up tents and tables with laptops to help dozens of seniors there choose among the myriad plan options available.

Bush visited with some waiting in a courtyard where Frank Sinatra's "Young At Heart" played on the loudspeakers, then he went indoors where people were looking over the laptops. He walked around giving handshakes and hugs to those who rose for his entrance, and greeted a man who remained sitting in a wheelchair with, "You look mighty comfortable."

Bush then flew to the Tampa, where he was greeted at the steps of Air Force One by his brother, Gov. Jeb Bush. The president playfully adjusted his brother's tie, then shook hands with Reps. Adam Putnam and Katherine Harris.

Harris, the former secretary of state famous for her role in the 2000 Florida recount that clinched Bush's White House bid, filed qualifying papers Monday to run for the Senate. But Jeb Bush said he doesn't think she can win and has asked Florida House Speaker Allan Bense to challenge her.

White House officials have also spoken supportively of Bense, but Harris didn't show any disappointment in her greeting to the president. She smiled, gripped his hand and spoke to him animatedly for several moments while news cameras caught the exchange.

Bush then motorcaded to a retirement community in Sun City Center, where he invited questions from the audience. Two women asked him about extending the deadline, including one who said there were logjams in the rush for those who have waited until end to sign up.

The government has added 6,000 operators and quadrupled its computer capacity for enrollment in anticipation of a rush this week.

Bush acknowledged the program is complicated and has caused confusion among some seniors. The Government Accountability Office said last week that federal investigators posing as senior citizens found that Medicare's operators routinely failed to give callers accurate and complete information about the drug benefit.

The Bush administration noted that the study was conducted Jan. 17-Feb. 7 and said those problems had been fixed. The White House hopes it has recovered from the early glitches and that the program will be a selling point for congressional Republicans in the November elections.