NEW YORK, March 22 - The UN secretary general, Antonio Guterres, has said it is time for Russia to end its “absurd” and “unwinnable” war in Ukraine, as the EU prepared to set up a “trust fund” aimed at helping Kyiv repel the invasion and rebuild afterwards, The Guardian reported.

Speaking to reporters at the UN’s headquarters in New York, Guterres said the war was “going nowhere, fast”. For more than two weeks, the devastated southern city of Mariupol had been encircled by Russian forces, bombed and shelled, he said.

“For what?” he asked. “Even if Mariupol falls, Ukraine cannot be conquered city by city, street by street, house by house.” Guterres said the only outcome of more fighting would be “more suffering, more destruction and more horror”.

Negotiators from Moscow and Kyiv have held several rounds of peace talks that have so far made little headway towards ending nearly four weeks of fighting, which have left thousands dead and displaced more than 10 million people.

“There is enough on the table to cease hostilities now and seriously negotiate now,” he said. “This war is unwinnable. Sooner or later, it will have to move from the battlefield to the peace table. That is inevitable.”

Leaders from the 27-nation EU will gather in Brussels on Thursday, meanwhile, to discuss the bloc’s further response to Moscow’s onslaught, including a longer-term financial support mechanism for Ukraine beyond ?1.2bn (£1bn) in emergency funding already agreed.

According to a draft document seen by Agence-France Presse, the EU will commit to “provide support to the Ukrainian government for its immediate needs and, once the Russian onslaught has ceased, for the reconstruction of a democratic Ukraine”.

The document did not provide details on the size of the Ukraine solidarity trust fund or how it might work, but said the European council expected preparations to start “without delay” and would call an international conference to raise cash.

The US president, Joe Biden, is also due to travel to Brussels this week for Nato and G7 talks to discuss further action, including tighter sanctions on Russia. Biden discussed Moscow’s “brutal” tactics in a call with European leaders on Monday.

Boris Johnson is expected to tell allies at the Nato summit that there is an immediate imperative to support the Ukrainians now, and that the Russian tactics using indiscriminate fire on civilian centres is inherently escalatory.

The UK will make the case that new action is needed amid Russia’s increased bombardment of cities such as Mariupol, and urge allies that they should consider this an escalation that requires a response including an increase in the flow of weapons to Ukraine that would improve their ability to resist.

Western officials are keen to avoid a view forming amongst allies that only use of chemical or biological weapons are considered a further escalation, rather than the increased indiscriminate shelling into civilian populations, which the UK believes could merit a further response.

The Commission on Wednesday will also set out plans to ensure that the more than 3.5 million refugees who have fled the Russian invasion have access to jobs, education and housing, vice-president Maros Sefcovic said on Tuesday. (om/ez)