Acknowledging that his refusal to ratify the Kyoto Protocol once created consternation in Europe, Bush said there was now a recognition that richer countries needed to "transfer out of the hydro-carbon economy".

"However, any binding emission targets will have to include China and India to be workable," Bush told The Times daily in an interview published on Wednesday.

Besides, he admitted that his gun-slinging rhetoric made the world believe that he was a "guy really anxious for war" in Iraq and said his aim now was to leave his successor a legacy of international diplomacy for tackling Iran.

Bush expressed regret at the bitter divisions over the war and said that he was troubled about how his country had been misunderstood. "I think that in retrospect I could have used a different tone, a different rhetoric."

Phrases such as "bring them on" or "dead or alive", he said, "indicated to people that I was, you know, not a man of peace".

He said he found it very painful "to put youngsters in harm's way". "I try to meet with as many of the families as I can. And I have an obligation to comfort and console as best as I possible can. I also have an obligation to make sure that those lives were not lost in vain."

Bush said his focus for his final six months in office is to secure agreement on issues such as establishing a Palestinian State and to "leave behind a series of structures that makes it easier for the next President".

Bush was also concerned that the Democratic Presidential nominee Barack Obama might open cracks in the West's united front towards Iran's nuclear ambitions.

On Tuesday, at the EU-US summit in Slovenia, he pressed for tougher sanctions against Iran unless it agreed to suspend its uranium enrichment programme verifiably, saying "they can either face isolation, or they can have better relations with all of us."

Bush told the newspaper that when his successor arrived and assessed "what will work or what won't work in dealing with Iran," he would stick with the current policy.

Asked about corruption allegations dogging Afghan President Hamid Karzai, Bush said: "I have found him to be an honest man."

He also offered words of encouragement to British Prime Minister Gordon Brown, whom he will meet on Sunday. He said Brown needed no advice on coping with political adversity as he is "plenty confident and plenty smart, plenty capable – he can sort it out."

But he delivered a thinly-veiled warning to Obama that his promises to renegotiate or block international trade deals were already causing alarm in Europe and beyond.