"I believe the next election will be difficult for the coalition, but we can win it," Howard told reporters.
"And I hope people understand from observing me in 30-odd years of public life that I have never run from a fight before and I don't intend to do so now," he added.
Analysts say Howard's commitment to fight could apply to any leadership challenge within his party as well as to the election, which could deliver the 68-year-old his fifth three-year term as national leader.
Howard, Australia's prime minister since 1996, ruled out allowing his lawmaker colleagues in the ruling Liberal Party to vote on whether he still holds majority support.
Howard said his party colleagues agreed in July 2006 that he was their best option to lead them to the next election, expected next month or November.
"That matter was resolved last year. It is not in the party's interests to revisit it," Howard said reporters. "That is my position; my very strong position."
Howard has said he expects the ruling Liberal Party-led coalition's popularity to rise once he has called the election, despite trailing the opposition Labor Party in opinion polls throughout the year.
Some observers say Howard should respond to successive bad polls by handing power to his 50-year-old party deputy Peter Costello, avoiding a divisive challenge.
Costello, the government's treasurer, has been pressuring Howard for years to hand him power. He declined to give media interviews Tuesday.
Sky News reported Tuesday that Foreign Minister Alexander Downer and Environment Minister Malcolm Turnbull want Howard to quit but that they have not asked him to do so. Both ministers' offices denied the Sky report.
Downer later said his colleagues had recently discussed whether Howard should go in light of consistently poor polling, but had resolved to stick with him.
"In terms of the leadership of the party and the leadership of the government, we are of the view that the best thing is to lock in behind John Howard," Downer told Sky.
Health Minister Tony Abbott said he backed Howard but would not say whether that view was shared by other Cabinet ministers.
Abbott said he would try to convince his colleagues at a Cabinet meeting Wednesday that Howard was the best man for the job, but did not rule out a leadership challenge.
"I think the best thing we can do is be steady under pressure, and certainly that is what I will try to be, and that is the counsel that I will give to any of my colleagues who might seek it," Abbott said.
Challenged by Labor leader Kevin Rudd to name an election date, Howard told Parliament the poll would be "any time between now and early December."
Against the backdrop of the threat of US sanctions, Mexico has refused to buy military helicopters from Russia