People in positions of power in Russia are actively promoting the idea of war, and conflict with Ukraine is now a distinct possibility, Nobel Peace Prize laureate Dmitry Muratov said on Friday.

Receiving his award at Oslo City Hall, Muratov said that in Russia it was common to think that politicians who avoided bloodshed were weak, while threatening the world with war was "the duty of true patriots".

Muratov, editor-in-chief of Russian newspaper Novaya Gazeta, won the 2021 award jointly with Maria Ressa of the Philippines, co-founder of news site Rappler, in recognition for their fight for freedom of expression. 

"The powerful actively promote the idea of war," he said. "Moreover, in (the) heads of some crazy geopoliticians, a war between Russia and Ukraine is not something impossible any longer."

US officials have said Russia could soon invade Ukraine following a build-up of troops near the Ukrainian border. Moscow has denied it is planning an invasion. 

Muratov also said journalism in Russia was going "through a dark valley", with over a hundred journalists, media outlets, human rights defenders and non-governmental organisations having been branded as "foreign agents".

"In Russia, this means "enemies of the people," Muratov said, dedicating his prize to "the entire community of investigative journalists" and his colleagues at Novaya Gazeta who lost their lives.

They include Anna Politkovskaya, gunned down in her apartment building in Moscow 15 years ago after angering the Kremlin with dispatches from the war in Chechnya.

Muratov's co-laureate Ressa reiterated her call for reform of social media platforms.

"Our greatest need today is to transform that hate and violence, the toxic sludge that's coursing through our information ecosystem, prioritised by American internet companies that make more money by spreading that hate and triggering the worst in us."

"For the US, reform or revoke section 230, the law that treats social media platforms like utilities."

Ressa and Muratov are the first journalists to receive the Nobel prize since Germany's Carl von Ossietzky won the 1935 award for revealing his country's secret rearmament programme.

Ressa noted in her speech that Von Ossietzky was never able to collect his award as he died in a Nazi concentration camp.

"By giving this to journalists today, the Nobel committee is signalling a similar historical moment, another existential point for democracy," she said.