Putin said the crisis exposed Western inconsistency and hypocrisy in backing some separatists while opposing others. He warned US of retaliation if it targeted RT.
Russian President Vladimir Putin said Thursday the Catalan crisis was Spain's internal affair but slammed what he called Western double standards over separatist movements.
"Russia's position is known here. All that is happening is Spain's internal business and must be resolved within Spanish law and on the basis of democratic traditions," Putin said at a meeting with international relations experts in the Black Sea city of Sochi.
However, he argued the crisis exposed Western inconsistency and hypocrisy in backing some separatists while opposing others - such as support for Kosovan independence, but opposition to Catalan claims.
"What we see is that in our partners' view there are worthy fighters for independence and there are separatists who cannot defend their rights.
"Such double standards - this is a very striking example of double standards - are fraught with serious danger for the stable development of Europe and other continents," Putin said.
The Russian leader said Western powers had long been aware of "the antagonism within Europe", referring to Catalonia.
"They knew, didn't they?" he said. "Yet in their day they practically welcomed the breakup of a whole number of European states, without concealing their glee."
He cited recognition of independence of majority-Albanian Kosovo from Russia's traditional ally Serbia.
"Why did they have to, so thoughtlessly, unquestioningly support Kosovo's breaking away?" Putin asked.
He accused European countries of "the wish, frankly, to please Big Brother from Washington" over Kosovo, saying this then provoked "similar processes in Europe and the world".
Moscow will retaliate if RT targeted by US
Putin said that Moscow will retaliate if the US takes measures against Kremlin-controlled media group RT.
Washington is pressuring the channel to register as a "foreign agent", which would force it to disclose personal information of employees and those interviewed.
Putin said Moscow would take similar actions against US media in Russia if legal steps are taken to limit RT's activities in the US.
"We will act in a way that reflects their moves and we will do this quickly. As soon as we see steps being taken that limit the actions of our media there will be a tit-for-tat response," he said.
RT this month said the channel was given a deadline of October 17 to register under the Foreign Agents Registration Act (FARA).
Relations between Moscow and Washington have plummeted to their lowest level since the Cold War.
Numerous ongoing investigations in the US are looking into whether Russia meddled in 2016 elections to swing the vote in favour of President Donald Trump.
Trump "should be respected"
Putin said US President Donald Trump should be respected because he has a democratic mandate.
"He has been elected by the American people and at least because of this he should be respected, even if we disagree with his position."