UNITED NATIONS - The world's top leaders should meet every three months, starting next year, until a plan is drawn up to reduce emissions blamed for global warming, former U.S. Vice President Al Gore said on Monday.

Gore, who has made climate change his signature issue since leaving the White House, told a U.N. meeting that presidents and prime ministers should go to Bali this year for talks on a follow-up pact to the Kyoto Protocol, which runs out in 2012.

Traditionally, environment ministers or lower-level negotiators attend the annual U.N. climate change talks, but Gore said leaders should go from now on and then hold follow-up meetings.

"I would like to propose ... that the heads of state around the world call an emergency session of this gathering for the beginning of next year to review the results of Bali," he said.

They should "continue to meet at the head of state level every three months until a treaty is successfully arrived at," Gore said. "We cannot continue business as usual."

The Kyoto Protocol requires 36 industrial countries to cut greenhouse gas emissions by at least 5 percent from 1990 levels by 2012. Leaders from the Group of Eight leading industrial nations pledged in June to find a follow-up deal for Kyoto by 2009.

U.N. Secretary-General Ban Ki-moon said he would consider Gore's proposals but said it was too early to say now what would be needed after the Bali meeting.

"I will seriously consider with the member states what action needs to be taken after we see the results of the Bali meeting," he told a news conference after the conference.

Reaching a new agreement will not be easy. The United States -- which did not ratify Kyoto -- has long resisted binding emissions targets, while Europe insists that mandatory limits are the only way to effectively fight climate change.

Developed and developing countries are also divided over the size and scope of their respective emissions restraints.

President George W. Bush, who defeated Gore in the 2000 presidential election, did not attend the U.N. climate change meeting but did attend a dinner with other leaders to discuss the subject on Monday night.

Gore said a post-Kyoto treaty should enter into force in 2010, two years earlier than planned.

"We simply cannot wait longer," he said. "There must be differentiated obligations, of course, but all nations must participate as part of the solution."

The former vice president also called for a moratorium on new coal-fired power plants that do not have facilities to trap and store carbon dioxide.