WASHINGTON -- President Barack Obama said he was reassessing the tense U.S. relationship with Russia because of a growing number of issues on which the two countries differ, and he called on Russian leader Vladimir Putin to "think forward as opposed to backward" and abandon a Cold War mentality.

Obama's comments at a White House news conference Friday came two days after cancelling a planned summit with Putin next month. Meanwhile, Secretary of State John Kerry and Defence Secretary Chuck Hagel ended talks with their Russian counterparts to see where co-operation is possible.

Those officials said they had made some tangible results on the push for a political solution to the crisis in Syria, among other issues.

Obama said Putin's return to the Kremlin last year had brought about "more rhetoric on the Russian side that was anti-American, that played into some of the old stereotypes about the Cold War contest between the United States and Russia."

He told reporters he decided not to attend the summit with Putin because "Russia has not moved" on a range of issues where the U.S. would like to see progress. He said his unhappiness with Russia granting asylum to National Security Agency leaker Edward Snowden was not the only reason.

Obama played down suggestions that he and Putin do not get along.

"I don't have a bad personal relationship with Putin. When we have conversations, they're candid. They're blunt. Oftentimes, they're constructive," he said.

But he took a shot at the often dour-looking Russian leader for his demeanour in meetings and appearances before reporters.

"He's got that kind of slouch, looking like the bored kid in the back of the classroom," Obama said. "But the truth is, is that when we're in conversations together, oftentimes it's very productive."

He urged Putin to think in broad terms and not view the United States as an enemy.

Obama also praised trade and arms control successes that the U.S. and Russia were able to seal when he was dealing with former Russian President Dmitry Medvedev.

His comments came shortly after Kerry and Hagel ended talks with their Russian counterparts that were intended to try to repair some of the damage caused by differences over Syria, Russia's domestic crackdown on civil rights and anti-gay legislation, a U.S. missile defence plan for Europe and other issues.

Officials from both countries said they had agreed to renew efforts to bring about a political resolution to the deteriorating situation in Syria at an international conference. On the military side, the officials said Russia had invited the U.S. to observe a joint Russian-Belarussian training exercise next year and to establish a video link between the defence chiefs.

Kerry said U.S.-Russia ties had been complicated by "colliding and conflicting interests." Russian Foreign Minister Sergey Lavrov called on both sides to act like "grown-ups."

Lavrov made it clear that Moscow had been prepared to sign agreements on trade and nuclear research and security had the Obama-Putin summit gone ahead. Russian Defence Minister Sergei Shoigu also attended the talks.