Washington (PTI): US President George W Bush has said that any international agreement on climate change cannot be effective without full participation of major economic powers like India and China.

"How can you possibly have an international agreement that's effective unless countries like China and India are not [sic] full participants," Bush said.

The issue of climate change came up during his meeting with visiting South Korean President Lee Myung-Bak at Camp David.

"And that's why I assured him (Lee) this major economies meeting that is taking place in Paris, I assured him ... that hopefully by the time we get to G8 there's a serious effort by all major economies to become active participants in a effective strategy to deal with this issue," Bush said at a joint press conference with Lee.

Bush said they discussed the issue and agreed to take a rational approach on it.

"We talked about our mutual desire to have a rational, practical approach to the international climate issue, global warming," Bush said.

On Thursday, Bush had announced a timeline of 2025 for the US to curtail emissions which contributed to the climate change.

"Countries like China and India are experiencing rapid economic growth -- and that's good for their people and it's good for the world. This also means that they are emitting increasingly large quantities of greenhouse gases -- which has consequences for the entire global climate," Bush had said.

A meeting of climate negotiators from 16 major countries on Friday in Paris failed to agree on specific goals for cutting emissions of the gases that cause global warming.

Meanwhile, on the issue of North Korean nuclear deal, Bush said a final decision on it was yet to be taken.

"We're going to make a judgment as to whether North Korea has met its obligations to account for its nuclear programme and activities, as well as meet its obligations to disable its reactor.

"We've laid out -- they've made some promises, and we'll make a judgment as to whether they met those promises" Bush said.

Bush said despite "rumours" floating concerning the negotiations, the US and its allies were still waiting to see the outcome of North Korea's overdue disclosures on its nuclear activities.

"Obviously I'm not going to accept a deal that doesn't advance the interests of the region. The whole objective of the six-party talks and framework is to get them to disclose their weapons programs, is to get them to dismantle their plutonium processing, is to get them to talk about activities, nuclear activities," Bush said.