Zelensky held talks with Swiss President Viola Amherd during a visit to Bern before heading to the World Economic Forum's annual meeting in the Swiss ski resort of Davos.

"Our teams from tomorrow are starting the preparation for holding in Switzerland a global peace summit," Zelensky told a press conference after the talks.

The summit "has to define that the end of the war has to be just", he said.

As for whether Russia would be invited, he said: "We are open to all countries of the world that respect our sovereignty and territorial integrity. Therefore you can draw conclusions on whom we invite."

"We would want the countries of the global south to be present, for sure," he added, and "we would want China to be involved".

No timescale was given for when the summit might be held.

Russia's war in Ukraine is set to enter its third year in February, and Moscow has intensified its aerial assaults on Ukraine in recent weeks.

"We would like to have a widely supported summit with as many countries as possible participating, in order to be successful," Amherd said.

"Once the time has come when we see that we can hold a successful summit, we will jointly organise that."

She said Bern wanted an "extensive, just and long-lasting peace in Ukraine".