Pope Francis has urged parties in the Ukraine war to "negotiate before things get worse", in an interview published Saturday by Swiss television.

The 87-year-old pontiff was asked by the public broadcaster RTS about a debate within Ukraine on whether to surrender to Russia's invasion, or if that would only legitimise the power of force.

"I believe that the strongest are those who see the situation, think about the people, and have the courage to raise the white flag and negotiate," he said in the interview, conducted in early February.

Speaking about war in general, including the Hamas-Israel war, he added: "Negotiations are never a surrender. It is the courage not to carry a country to suicide."

"That word negotiate is a brave word. When you see that you are defeated, that things are not working out, to have the courage to negotiate," he said.

The head of the worldwide Catholic Church said people might be ashamed but asked how many lives were being lost.

"Today, for example with the war in Ukraine, there are many who want to act as mediators. Turkey for example," he said.

"Don't be ashamed to negotiate before things get worse."

He was also asked about the Israel-Hamas war, where he laid blame on both sides.

"War is made by two, not one. The irresponsible ones are these two who wage war," he told the broadcaster.