U.S. President Barack Obama gestures during his interview with The Associated Press on Thursday in the West Wing of the White House. (Pablo Martinez Monsivais/Associated Press)

On the eve of a trip to Moscow, U.S. President Barack Obama scolded Russian Prime Minister Vladimir Putin on Thursday for keeping "one foot in the old ways of doing business."

By contrast, he said, Putin's hand-picked successor, President Dmitry Medvedev, understands that Cold War behaviour is outdated.

In a wide-ranging White House interview with The Associated Press, the president said he will meet with both Putin and Medvedev on his trip, in hopes they can "move in concert in co-operating with us on some critical issues."

Obama also said he is not reconciled to Iran obtaining a nuclear weapon within a year and did not rule out sending additional U.S. soldiers to Afghanistan.

Scheduled to leave next week on a trip to Russia, Italy and Ghana, Obama praised Moscow for its co-operation in attempting to persuade North Korea and Iran to abandon their nuclear development programs.

The United Nations recently approved "the most robust sanction regime that we've ever seen with respect to North Korea," Obama said.

The president said his agenda in Russia includes talks on a new treaty to curtail long-range nuclear missiles. North Korea test-launched four short-range missiles on Thursday.

Russian Prime Minister Vladimir Putin speaks at a publication party for a book in Tokyo in May. (Associated Press)

Reservations over policy

Asked why he intends to meet with Putin, Obama said the former president "still has a lot of sway."

"And I think that it's important that even as we move forward with President Medvedev that Putin understand that the old Cold War approaches to U.S.-Russian relations is outdated; that it's time to move forward in a different direction," he said.

Obama also expressed reservations about his recently announced policy that could lead to indefinite detention for some of the detainees currently at the Guantanamo Bay prison.

"It gives me huge pause," he said, to the point where he may not see it through.

"We're going to proceed very carefully on this front, and it may turn out that after looking at all the dimensions of this, that I don't feel comfortable with [it]," Obama said.

The president has pledged to close the prison in Cuba and hopes to send most of those currently held there to other countries.

Mideast nuclear arms race 'recipe for potential disaster'

Asked if he was resigned to Iran's possession of nuclear weapons, he said, "I'm not reconciled with that, and I don't think the international community is reconciled with that."

The president said a nuclear-armed Iran probably would trigger an arms race in the already volatile Middle East and said that would be "a recipe for potential disaster." Iran says its nuclear program is intended to produce electricity, not weapons.

On Afghanistan, Obama said that he will reassess the possible need for additional U.S. troops after the Afghan national elections in August.

Asked how he defines U.S. success in Afghanistan, the president said the main U.S. goal is to keep al-Qaeda from acquiring a haven from which it can train fighters and launch attacks on the United States or its allies.

He said the United States and its allies also must build up the Afghan national army and police and enable neighbouring Pakistan to secure its borders against extremist movements.

On domestic issues, the president said he had made some progress in stabilizing the economy, but he conceded too many jobs are still being lost.

He said he was "deeply concerned" about unemployment and conceded that too many families are worried about "whether they will be next."

Still, he said that since he took office almost six months ago, his administration has successfully stabilized the financial markets and started to see some stabilization on housing.

Since Obama signed the $780-billion US economic stimulus bill in February, the U.S. economy has shed more than two million jobs.