U.S. President Barack Obama said?in Oslo?on Thursday that the U.S. strategy in Afghanistan is correct and his administration will start pulling out of troops from the Asian country in July 2011 as scheduled.

"We get the correct strategy in Afghanistan ...and we will execute it," Obama told a joint press conference with Norwegian Prime Minister Jens Stoltenberg.

Obama said he was "unambiguous" about his July 2011 date for the start of a U.S. drawdown in Afghanistan, adding there should be no debate about his decision.

The Norwegian prime minister promised that his country will increase its contribution to Afghanistan. "Norway will increase its financial contribution to Afghanistan," he said.

Obama was here to accept the Nobel Peace Prize in a ceremony in Oslo City Hall starting at 1200 GMT.

About the prize, Obama said with a humble attitude that "it's a great surprise, and others may be more deserving it."

Obama and his wife, Michelle, arrived in Oslo after an overnight flight from Washington for the Nobel Peace Prize just nine days after he ordered 30,000 more U.S. troops to Afghanistan.

The Nobel committee announced earlier that Obama had won the peace prize when he took office less than nine months, for "his extraordinary efforts to strengthen international diplomacy and cooperation between peoples" and his push for nuclear disarmament.

However, polls showed that a majority of Americans feel Obama does not deserve the prize.