Dmytro Kuleba says Ukraine has told the African presidents' peace initiative that seceding Ukrainian territory to Russia is a non-starter in peace negotiations, and no peace plan should propose freezing the conflict and then trying to fix it afterwards.

Ukraine has welcomed the fact that Russian President Vladimir Putin may not visit South Africa for the BRICS summit in August because Pretoria is concerned it would have to arrest him under an International Criminal Court (ICC) warrant.

Ukrainian Foreign Minister Dmytro Kuleba said it was entirely up to South Africa to decide whether to move the BRICS summit to China, as Pretoria is contemplating doing to avoid having to arrest Putin.

"But the very fact that it is getting more and more difficult for Putin to go anywhere in the world is welcome," Kuleba said in an online briefing for African journalists on Wednesday.

He said the most important thing for every respectable country was to respect rules and principles.

South Africa, as a party to the ICC Rome Statute, should not allow Putin "to step on South African soil, or it should arrest him".

Kuleba also welcomed the peace initiative to Ukraine and Russia which President Cyril Ramaphosa and other presidents plan to undertake later this month.

"We see value in talking to them," he said, though adding that if the African leaders had a peace plan, they had not yet shared it with Ukraine.

But he stressed...