UNITED NATIONS, United States, (AFP) – The UN General Assembly meets Monday hours after Russia launched a deadly barrage of missile strikes at cities across Ukraine, as Western powers condemned Moscow’s latest attacks and sought to underscore its isolation.

The United Nations called the urgent meeting to discuss Russia’s declared annexation of four partly occupied Ukrainian regions, but the debate was set to be overshadowed by the attacks on Kyiv and other cities in one of the most punishing assaults on Ukraine in months.

Russian President Vladimir Putin vowed even more “severe” retaliation after the recent explosion that damaged a key bridge in Moscow-annexed Crimea — an attack the Kremlin has blamed on Kyiv.

Ahead of the General Assembly session, and with tensions at a boiling point, UN chief Antonio Guterres described Russia’s attacks as an “unacceptable escalation of the war,” his spokesman said.

US President Joe Biden meanwhile condemned the strikes in stark terms, saying they “demonstrate the utter brutality” of Putin’s “illegal war.”

“The United States strongly condemns Russia’s missile strikes today across Ukraine,” he said in a statement.

– ‘Illegal annexations’ –

With Putin’s actions in the spotlight, UN debate will open on a draft resolution denouncing what has been widely seen in the West as Russia’s illegal seizure of Ukrainian land.

The decision to bring the annexation matter before the General Assembly, where the 193 UN members have one vote each — and no one wields veto power — was taken after Russia used its veto in a Security Council meeting September 30 to block a similar proposal.

The vote is expected no sooner than Wednesday.

“It’s extremely important,” said Olof Skoog, who, as EU ambassador to the world body, drafted the text in cooperation with Ukraine and other countries.

The international community will be in “a very, very bad place,” the Swedish diplomat told reporters, “unless the UN system and the international community through the General Assembly react to this kind of illegal attempt.”

A failure by the General Assembly to act would give “carte blanche to other countries to do likewise or to give recognition to what Russia has done,” he added.