US presidential candidate Barack Obama has reassured Prime Minister Gordon Brown over his plummeting popularity.
Speaking outside 10 Downing Street after two hours of talks, Senator Obama said he had no advice for Mr Brown.
But he said: "You're always more popular before you're actually in charge. Once you're responsible then you're going to make some people unhappy."
Mr Obama said he and Mr Brown had talked about strengthening the relationship between the US and Britain.
He said he had thanked Mr Brown for Britain's "stalwart assistance" over issues such as Afghanistan and knew British troops had "borne a heavy price".
The Democrats' candidate said he has already committed to increasing the number of troops in Afghanistan if he is elected.
But he hinted that Britain would also be expected to offer support when he added: "We'd like that burden shared."
He said his meeting with Mr Brown had been "wonderful" and said the two leaders discussed how to strengthen the transatlantic relationship on issues such as climate change, international terrorism and financial markets.
He said the relationship was important "to solve problems that can't be solved by any one country".
He added: "I'm looking forward to the possibility of seeing the United States and Great Britain taking the lead." Asked if there was a special relationship between the US and the UK he replied: "Absolutely".
