“We said many times that the process of (peace) talks without Russia makes no sense,” said Kremlin spokesman Dmitry Peskov.

Russian President Vladimir Putin mocked the conference, saying during a meeting with his Belarusian ally and counterpart Alexander Lukashenko that “it would be funny if it were not sad”.

Russia’s foreign ministry spokeswoman Maria Zakharova said any action on Ukraine that “ignores Russia’s position” was “detached from reality” and had “no perspective”.

US general says Ukraine could be outgunned by Russia ‘10 to 1’ in weeks

She also criticised the “peace formula” put forward by President Volodymyr Zelensky, which calls for the withdrawal of Russian troops from Ukrainian territory, financial reparations from Moscow and the creation of a special tribunal to judge Russian officials.

“It is common knowledge that the ‘Zelensky formula’ does not envisage compromises or alternatives and totally ignores the proposals of China, Brazil, African and Arab states,” Zakharova said.

She also said Switzerland “cannot be trusted” to be neutral because it “defends Ukraine’s positions, supports the Kyiv regime, applies anti-Russian sanctions and adopted strategies that exclude Russia from the European security system”.

The United States said it had not yet decided on its participation at the conference but scoffed at earlier Russian allegations that the summit would be a pre-election project by President Joe Biden’s Democratic Party.

“Obviously, that is an absurd allegation by the Russian government,” State Department spokesman Matthew Miller told reporters.

“If this is a diplomatic meeting that the Ukrainian government supports and wants to engage in, we certainly support their right to do so,” he said.

The Swiss government agreed during a January visit by Zelensky to organise a peace conference this year.

It said in a statement on Wednesday that “there is currently sufficient international support for a high-level conference to launch the peace process”.

Traditionally neutral Switzerland has from the start insisted that Moscow must eventually be brought into the talks and has sought to attract China and other emerging powers to the conference.