Ukraine’s western allies have called for “additional work” on a US-Russia peace plan and for the EU and Nato to be given a say over its contents as they seek to delay the terms being forced on Kyiv.

The 14 leaders, from countries that include European states plus Japan, Australia and Canada, said on Saturday that the “initial draft of the 28-point plan includes important elements that will be essential for a just and lasting peace”, in a joint statement agreed at an emergency meeting in Johannesburg.

“We believe therefore that the draft is a basis which will require additional work,” the leaders said. “We reiterate that the implementation of elements relating to the European Union and relating to Nato would need the consent of EU and Nato members respectively.”