The US will bring together delegations from Ukraine and Russia in Abu Dhabi next week for talks on ending Moscow's war against Ukraine US envoy Steve Witkoff has said.

In a social media post, Witkoff said the discussions will cover "post-war security agreements, de-escalation, humanitarian measures, and ending the war". Witkoff and Donald Trump's son-in-law Jared Kushner are expected to represent the US at the talks, Reuters quoted a senior US official as saying.

Russian president Vladimir Putin agreed to a new round of trilateral talks after meeting Witkoff in St Petersburg two weeks ago.

Witkoff also said in his post that US negotiators would meet this week in Brussels with representatives from the UK, France, Germany, the EU and Nato to discuss "security guarantees for Ukraine, Europe's post-war security architecture and economic opportunities to support Ukraine's reconstruction". Ukraine and Russia remain far apart on the terms of any possible peace deal. The last US-mediated trilateral peace talks took place in February before the US and Israel launched a war against Iran.

Russian forces bombed a school used as an aid distribution point in a village in Ukraine's south-eastern Zaporizhzhia region on Monday, killing 26 people Volodymyr Zelenskyy and the country's emergency services said. "The Russians struck first just as people were arriving – a few aerial bombs," the Ukrainian president said. "Then there was a second strike – more air bombs, this time on the shelter.

A vile terrorist strike." About 2,800 troops from 10 European countries will this month stage in Poland the first exercise of a new multinational force in support of Ukraine London and Paris said on Tuesday. Led by France and the UK, the "Multinational Force – Ukraine" (MNF-U) has no offensive mission and is only to be deployed once a ceasefire is agreed to end the war triggered by Russia's 2022 invasion.

"The exercise will allow the testing of the speed and efficiency at which several nations can deploy forces on land, sea and air to support Ukraine once hostilities have finished," the joint statement released by the French defence ministry said. "This isn't a hypothetical plan, it's a real force, ready to help Ukraine once the fighting stops," the UK defence minister, Wes Streeting, was quoted as saying in the UK statement.

The exercise is scheduled to run from 9-22 November in south-east Poland, not far from the Ukrainian border. Unknown hackers targeted Ukraine's nationwide emergency alert mobile app sending residents in Kyiv a warning that they were at risk of an imminent nuclear strike. It also wrongly warned of a chemical threat to the Ukrainian capital and street-to-street fighting, Luke Harding reports "I was briefly terrified," one woman said.

Ukraine has accused Russia of taking advantage of the US-backed humanitarian ceasefire last week in the southern Kherson region to strengthen its military position there. Nearly 800 people were evacuated from the Russian-occupied Ukrainian town of Oleshky, according to the US. Both sides have praised the six-day pause in fighting around the town as a success. But on Monday Kyiv's general staff said Russian forces had also used the truce to rotate troops, boost defences and improve battlefield logistics. Kremlin spokesperson Dmitry Peskov said he did not have specific information on any movements, but that adjusting positions during a ceasefire was "standard practice" and it was safe to assume Ukraine had done the same.