David Cameron denies split with US over spending cuts
David Cameron has said there is "no difference" between the US and UK on his plans for cuts, as he prepares for his first G8 summit.
US President Barack Obama has warned G20 leaders not to withdraw economic stimulus packages too early.
Mr Cameron, who backs spending cuts, said the US accepted that those with the biggest deficits had to "accelerate the process of dealing with them".
Leaders of G8 industrialised nations are meeting in Muskoka, Ontario.
They will discuss help for the poorest countries ahead of a meeting of the G20 in Toronto on Saturday which will focus on the global economy.
'Mistakes of the past'
US Treasury Secretary Timothy Geithner told the BBC that Europe must focus on growth, as well as cuts, and President Obama warned European leaders last week they had to learn from the "mistakes of the past when stimulus was too quickly withdrawn and resulted in renewed economic hardships and recession".
Asked by BBC Political Editor Nick Robinson if he thought Mr Obama was nervous about the UK's plans to cut spending - outlined in the Budget this week - Mr Cameron said: "No, I don't think so.
"I think in the British case, the Americans and others absolutely accept that those of us with the biggest deficits ... have to accelerate the process of dealing with them because the big risk to our economies is actually... not dealing with the deficits. There's no difference between us and the Americans on that."
He said he wanted to "get the right outcome for the world economy" over the weekend adding: "That means those countries like our own with big budget deficits have got to move faster, other countries with surpluses can afford to do different things. We need to deal with those imbalances in the world economy."
On economic stimulus, he said he wanted to push for the "greatest stimulus of all" - free trade and countries should be breaking down barrier.
"That's a stimulus that doesn't cost any money and I will be pushing hard for better language on that so we can make more progress."
Earlier he told Canada's Globe and Mail newspaper the summits should be "more than just grand talking shops" and focus on the global economy, reforming banks and boosting trade.
He said there should be "fresh thinking and renewed political leadership" on issues like trade, aid and the global economy, and the summits should focus on delivering concrete results and international meetings too often "fail to live up to the hype".
But shadow foreign secretary David Miliband told BBC Radio 5live Mr Cameron's words suggested he felt the summits were "a bit of a waste of time" which he said was a "slightly odd way of going into your first meeting" [as prime minister].
"I'm not sure I would recommend that as a diplomatic strategy," he said.
He said the G20 meetings were "vital" and last year's summit in London had been "very significant in rescuing the global economy from the depression that was genuinely threatened".
On Friday morning Mr Cameron held meetings with Italian Prime Minister Silvio Berlusconi and Canadian PM Stephen Harper.
He is also meeting Russian President Dmitry Medvedev for talks - something Downing Street said would provide "an opportunity for a better relationship between our two countries".
Mr Cameron will meet US President Barack Obama, Mr Medvedev and Chinese Premier Hu Jintao later on Friday and is expected to hold one-to-one talks with President Obama on Saturday.
It will be his first meeting with the US president since taking office last month and is likely to be dominated by the military campaign in Afghanistan and BP's continuing efforts to stop the oil spill in the Gulf of Mexico, following the fatal explosion on the Deepwater Horizon oil rig.
The two leaders are expected to reaffirm their commitment to Nato's strategy in Afghanistan despite the sacking of its top military commander in the country, Gen Stanley McChrystal, for criticising White House officials.
In a phone call on Thursday, No 10 said Mr Cameron had impressed on the US president the determination of Lt Gen Nick Parker, the British officer who has taken acting command of operations, that the mission should not "miss a beat" during this period.
The G20 meeting is expected to focus on efforts to support growth in the global economy while reducing national deficits as well as individual countries' proposals for bank taxes.