WASHINGTON— Mayor Bloomberg is headed to the nation’s capital today to deliver a speech at a major health policy summit and to meet with the secretary of state, Condoleezza Rice, to lobby for help in keeping the United Nations in New York.

Mr. Bloomberg is headlining the first day of the Academy Health National Health Policy Conference, an annual two-day forum that brings together federal, state, and local officials and members of both political parties.

While City Hall would offer no details on what the mayor plans to say, organizers have been told he will offer his perspective on “health reform.” The topic could inject Mr. Bloomberg into the widening political debate over how to control the rising costs of health care and insurance. The issue has already emerged as a dominant domestic policy concern in the new Congress and the 2008 presidential campaign.

The Bush administration wants to offer tax breaks to individuals who buy private insurance, a proposal panned by many Democrats, particularly those who are renewing calls for universal health coverage.

The administration’s proposal to slash billions from Medicare and Medicaid has drawn harsh criticism from the president of the city’s Health and Hospitals Corporation, Alan Aviles, who has estimated that it would cut $350 million in federal funding to public hospitals in New York.

The mayor’s lunchtime speech at the Capital Hilton will come hours after two aides to President Bush will brief the conference on the administration’s health policy agenda.

Mr. Bloomberg is scheduled to meet later in the day with Ms. Rice at the State Department. A mayoral spokesman, Stuart Loeser, said Mr. Bloomberg wanted to talk to Ms. Rice about the necessary steps to keep the U.N. headquarters in the city, an issue he is also taking up with Albany. While the U.N.’s presence in the city has long been a source of consternation for critics of the world body, the mayor has consistently advocated for it to remain, saying it provides more than 18,000 jobs and $2.2 billion in annual economic benefits.

The Bloomberg administration’s proposed 2008 budget calls for $63 million in federal funding for providing security for the U.N. The city also wants foreign countries to settle up for $19 million in unpaid parking tickets.

The administration is lobbying state lawmakers to support a new 35-story home for the U.N. along the East River, an idea that has faced opposition from those who cite the U.N.’s recent corruption scandals and who say its policies are anti-American.

The mayor has been a regular visitor to the nation’s capital of late. This will be his third official trip to Washington in the first six weeks of 2007; previously he has lobbied the Senate for more homeland security funding and convened a summit of his national coalition against illegal guns. Mr. Bloomberg has traveled frequently out-of-state in his second term, though he routinely denies speculation that he will use an elevated profile to mount a bid for the White House next year.

Still, there are clear signs he relishes the national stage. An organizer of the health policy conference said officials initially asked the city for a health official, such as the department commissioner, Dr. Thomas Frieden, to address the forum, noting the city’s reputation for aggressive public health policy. But a few weeks ago the mayor’s office contacted them and said Mr. Bloomberg would speak. “Of course we were happy to oblige,” the organizer, who asked not to be identified, said.

Far-reaching public health initiatives have been signatures of Mr. Bloomberg’s tenure; he has drawn national attention for successfully pushing to ban smoking in bars and restaurants and more recently for outlawing the use of most artery-clogging trans fats in city eateries. On the national front, the Republican mayor has also spoken out repeatedly in favor of stem cell research, distancing himself from the Bush administration and many members of his party.