U.S. President Barack Obama said Tuesday he was "disappointed" by Russia's decision to grant asylum to Edward Snowden, the former intelligence contractor who leaked details of vast U.S. surveillance programs.

"I was disappointed, because even though we don't have an extradition treaty with them, traditionally we have tried to respect if there's a lawbreaker or alleged lawbreaker in their country," Obama said during an appearance on a late-night comedy show.

U.S. Secretary of State John Kerry and Defense Secretary Chuck Hagel will meet their Russian counterparts Sergei Lavrov and Sergei Shoigu on Friday in Washington, a U.S. defense official said.

The so-called "2+2" meeting, to be held at the State Department, comes at a time of tensions between Washington and Russia over Moscow's decision to grant asylum to U.S. intelligence leaker Edward Snowden.

Russia on Tuesday backed the new Iranian president's call for fresh negotiations without delay on Tehran's nuclear program, while criticizing calls by U.S. lawmakers for harsher sanctions against Iran.

Iranian President Hasan Rowhani said Tuesday at his first news conference since assuming office that Iran was ready for "serious" talks on its nuclear program "without wasting time."

Russia's deputy foreign minister on Tuesday slammed the United States for questioning whether President Barack Obama would meet his Russian counterpart in September after Moscow gave asylum to fugitive Edward Snowden.

"The U.S. administration is bringing into question bilateral contact at the highest level. I think this is absolute distortion of reality, it's looking at the world in a crooked mirror," deputy foreign minister Sergei Ryabkov said in an interview with the Interfax news agency.

The secrets of Russian President Vladimir Putin's buff physique and youthful appearance are the result of herbal health remedies and swimming regularly to combat stress, his doctor revealed Monday.

Putin "doesn't look his age", the Kremlin's top doctor Sergei Mironov told Russian weekly Itogui, chiefly because the 60-year-old is "skeptical about medication".

A Muslim cleric in Russia's restive Dagestan was shot dead in an ambush, investigators said Sunday, the latest in a string of murders of moderate religious figures in a province plagued by an Islamist insurgency.

Gunmen opened fire on 66-year-old Ilyas Ilyasov on Saturday as he was getting into his car near his home in Makhachkala, the largest city in the region, Russia's Investigative Committee said in a statement.

Russian President Vladimir Putin said Friday he found it "strange" that his biggest critic Alexei Navalny was sentenced to five years in prison while a man convicted in the same case was let off with a suspended term.

The remark was the first by the Russian leader on the ruling against his arch foe, who was convicted of fraud last month.

Russia's awarding of asylum to U.S. leaker Edward Snowden dealt a new blow to already bruised relations between Moscow and Washington but it remains in their interest to prevent the row from erupting into a Cold-War style crisis, analysts said.

Washington immediately rebuked Moscow for granting one year asylum to a man the United States wants to put on trial for leaking details of a vast U.S. intelligence program.

U.S. ambassador to Moscow Michael McFaul and President Vladimir Putin's top foreign policy aide Yury Ushakov met on Friday to discuss issues including the "new status" of intelligence leaker Edward Snowden, the American embassy said.

"They discussed reducing nuclear weapons, missile defense, Syria, trade, human rights and new status of Mr Snowden," the embassy wrote on its Twitter feed a day after Snowden was awarded asylum by Russia.

Russia on Friday faced fury from the United States after granting asylum to fugitive intelligence leaker Edward Snowden, whose whereabouts are now a mystery after he was finally able to walk free from an airport transit zone where he was marooned for over five weeks.

The White House said it was "extremely disappointed" by Moscow's decision, adding that it would now review if a U.S.-Russia summit in September is necessary.