Russia is ready to sever ties with the EU if the bloc imposes new, economically painful sanctions, Russian Foreign Minister Sergei Lavrov says.
The EU has raised the prospect of further sanctions amid a row over the treatment of the jailed Russian opposition leader, Alexei Navalny.
When an interviewer asked if Russia was heading for a "break" with the EU, Mr Lavrov said "we're ready for that".
"If you want peace, prepare for war," he said.
He said a break in ties could be triggered by EU sanctions that "create risks for our economy, including in the most sensitive areas".
"We don't want to isolate ourselves from world affairs, but we have to be prepared for that." He was speaking on the Russian YouTube channel Solovyov Live.
In the past week Russia and the EU have expelled three of each other's diplomats in a tit-for-tat dispute centering on the Navalny case.
Russia went first, a week ago, saying three EU diplomats had attended an illegal pro-Navalny protest - an allegation rejected by the EU. The Russian announcement came during a visit by EU foreign affairs chief Josep Borrell.
This week the EU countries involved - Germany, Poland and Sweden - expelled three Russian diplomats.
More EU sanctions?
Mr Borrell told MEPs in the European Parliament on Tuesday that the next step "could include sanctions, and I will put forward concrete proposals".
Last October the EU imposed sanctions on six top Russian officials and a Russian chemical weapons research centre, accusing them of direct involvement in the poisoning of Navalny in August. The attack with the weapons-grade nerve agent Novichok nearly killed him.
Many of President Vladimir Putin's close aides are now under EU and US sanctions, that is, asset freezes and travel bans. They date back to Russia's annexation of Ukraine's Crimea peninsula in 2014.
Dozens of MEPs have called for Mr Borrell to resign, saying his Moscow trip was "humiliating", but EU leaders have not backed them.
He told MEPs the Kremlin had left "no opening for democratic rule of law". It was crushing any alternatives to President Putin, he said. "They are merciless in stifling any such attempts."
Navalny back in court
Navalny is in court again to face allegations that he defamed a World War Two veteran. The anti-corruption campaigner says it is a further fabricated case aimed at blackening his name.
This month he was sentenced to nearly three years in prison in a separate case, widely seen as politically motivated.
On 22 February EU foreign ministers will meet and are expected to discuss more sanctions on Russia.
Despite the souring of ties with the Kremlin, Germany is going ahead with the huge Russian Nord Stream 2 gas pipeline project. It is very controversial - EU partners Poland and the Baltic states oppose it strongly.
This week German President Frank-Walter Steinmeier said "energy ties are almost the last bridge between Russia and Europe".
Speaking to the German daily Rheinische Post, he recalled the huge losses suffered by Russia in World War Two at the hands of Nazi Germany. "That doesn't justify any wrongdoing in Russian policy today, but we mustn't lose sight of the bigger picture."