WASHINGTON - Sen. John Kerry said yesterday that he is forming an exploratory committee this week in anticipation of a 2004 bid for the White House.

"It's an enormous step, and it's not one I take lightly, but it's one that I'm excited about," the Massachusetts Democrat and decorated Vietnam War veteran said on NBC's Meet the Press. "It's a challenge."

Kerry's move was widely expected. Once he files the papers to launch a committee, he can begin raising money to gauge whether he has backing as a serious presidential candidate. A formal announcement of his candidacy is "down the road some months," he said.

A recent Los Angeles Times poll of Democratic Party insiders found strong support for Kerry as the party's presidential candidate. The poll found no clear-cut favorite, but when read a list of 10 prospective nominees, 19 percent of those surveyed named former Vice President Al Gore, the party's presidential candidate in 2000, as their top choice, and 18 percent named Kerry. Nearly half those polled said Gore should sit out the race.

The Democratic field is expected to be crowded. Vermont Gov. Howard Dean already is exploring a bid. Missouri Rep. Richard A. Gephardt and North Carolina Sen. John Edwards have also expressed interest. Gore has said he will make up his mind by January . His running mate in 2000, Sen. Joseph I. Lieberman of Connecticut, has said he will run if Gore doesn't.

"There are good people who are standing up. There are others who will contest. That's part of the process," Kerry said. "I want this to be a contest of ideas, and I want it to be based not on my running against anybody, but running for a vision for this country."

There is, he said, "deep anxiety" in America about "job security, income security, retirement security, health security, education security, physical, personal security and, of course, national security. And, I think, literally on almost every issue facing the country, I believe there is a better choice for this nation."

Soon after graduating from Yale University in 1966, Kerry entered the Navy, where he served on a gunboat in the Mekong Delta in Vietnam. He was awarded a Silver Star, a Bronze Star and three Purple Hearts for his combat service. When he returned from Vietnam, he began questioning U.S. involvement in that conflict, becoming a spokesman for Vietnam Veterans Against the War.

Kerry, 58, was a lawyer and prosecutor in Massachusetts before being elected lieutenant governor in 1982. He was elected to the Senate two years later and was unopposed when he ran for a fourth term last month.

In the Senate, he helped lead the investigation into the Iran-contra affair and helped expose scandals at the Abu Dhabi-based Bank of Credit and Commerce International, which closed in 1991 after it was linked to secret weapons deals, drug money and terrorists.

Kerry has been a vocal critic of President Bush's policy against Iraq, urging that Bush first go to the United Nations. Kerry ended up voting for the congressional resolution supporting U.S. action against Baghdad, though. He voted against the gulf war in 1991. He has been sharply critical of Bush's Middle East policy as well, repeating his complaint yesterday that the administration has disengaged from that area of the world during its first year in office. He also opposes Bush's tax cuts, saying they favor the rich.

"As people get to know me in the course of this, they'll know the things that I have fought for and the things I stand for," Kerry said on NBC.

Lisa Getter writes for the Los Angeles Times, a Tribune Publishing newspaper.