Washington ? President Bush, under international pressure to take tough action against global warming, on Thursday called for a summit of the United States and other nations that spew the most greenhouse gases on the planet.

The goal: set a long-term global strategy for reducing emissions – and counter allegations that the United States is foot-dragging.

The White House said the president’s proposal addresses “life after” the Kyoto Protocol expires in 2012, and he wants to bring India, China and other fast-growing countries to the negotiation table so they are part of the solution, not the problem.

“The United States takes this issue seriously,” Bush said.

Critics disagree. They say Bush wants to set unenforceable targets for curbing greenhouse gas, not concrete limits on emissions. They contend he is ignoring other international efforts on climate change that are already under way, and is trying to avoid taking action until he leaves office.

David Doniger, climate policy director for the Natural Resources Defense Council, said Bush will have no credibility with the countries he wants to bring to the table unless he’s committed to specific limits to cap the United States’ own contributions to global warming.

“The president is warming up to throw his opening pitch while business, states and the rest of the world are already at the top of the ninth inning,” Doniger said. “It is nothing less than embarrassing that three of the world’s biggest oil companies are calling for tougher measures than the White House.”

House Speaker Nancy Pelosi, just back from a climate change fact-finding trip to Greenland and European capitals, said getting nations to set voluntary emissions targets was not enough to reverse warming of the planet.

“Today’s announcement fails to respond to the severity of the crisis that most of the rest of the world has long since recognized,” she said.

The president outlined his proposal in a speech just days before he attends a summit in Germany of leading industrialized nations. Global warming is a major topic on the agenda and Bush will be on the spot.

“The new initiative I’m outlining today will contribute to the important dialogue that will take place in Germany next week,” he said.

The administration is resisting parts of a climate change initiative being pushed by the host of the G-8 meeting, German Chancellor Angela Merkel. She backs a plan that would limit the average global temperature increase to 3.6 degrees. Practically, experts say that would require – by 2050 – a global reduction in emissions of 50 percent below 1990 levels.