Russian President Vladimir Putin said Wednesday that the United States' 20-year campaign in Afghanistan ended in "only tragedies, only losses."

The Russian leader has a track record of criticising Western countries for trying to impose their values on non-Western nations.

Moscow has regularly slammed the US policy in Afghanistan, which is now controlled by the Taliban after their takeover this month ahead of the American pullout on August 31.

Putin said Wednesday that the US army tried to "engrain their norms" in war-ravaged Afghanistan for two decades, which he characterised as a futile exercise.

-The result is only tragedies, only losses for those that did it -- for the US -- and even more so for the people who live on Afghan territory- he said.

It is "impossible to impose anything from outside", he said.

He was speaking at a meeting with teenagers in the Russian far eastern city of Vladivostok to mark the start of the school year.

Last week Putin said Russia would not interfere in Afghanistan and that Moscow had learned from the Soviet occupation of the country.

He has also complained about Western countries trying to place Afghan refugees in Moscow-allied Central Asian states.

Moscow has been cautiously optimistic about the new leadership in Kabul, saying it would not meddle in domestic affairs.