Washington and its allies said Wednesday they will investigate a deadly strike in Poland before deciding next steps, with US President Joe Biden saying it was "unlikely" the missile was fired from Russia.
"We agreed to support Poland's investigation into the explosion," Biden told reporters after a hastily arranged gathering of allies on the sidelines of the G20 in Bali, Indonesia.
"We're going to make sure we figure out exactly what happened... and then we're going to collectively determine our next step," added Biden after talks with G7 and other European leaders.
Asked if the missile, which killed two people in a village near the Ukrainian border, had been fired from Russia, Biden said there was "preliminary information that contests that".
"It's unlikely... that it was fired from Russia. But we'll see."
The explosion in Poland, a NATO member, immediately sparked concerns that the alliance might be drawn into Russia's nearly nine-month war against Western-backed Ukraine.
UN Secretary-General Antonio Guterres, also in Bali, warned it was "absolutely essential to avoid escalating the war in Ukraine."
And Polish President Andrzej Duda also urged calm, saying there was no "unequivocal evidence" for where the missile came from and that he saw it as an "isolated" incident.
"Nothing indicates to us that there will be more," he said.
The foreign ministry earlier summoned Russia's ambassador to Warsaw to give "immediate detailed explanations" over the strike, which Moscow has denied launching.
Poland is now expected to request urgent consultations under Article 4 of the NATO Treaty, which is invoked when any NATO member feels their "territorial integrity, political independence or security" are at risk.
Ukrainian President Volodymyr Zelensky blamed Russia for the Poland blast.
The incident came after Russia launched a wave of missile strikes across Ukraine on Tuesday that left millions of households without power and were described by Zelensky as a "slap in the face" for the G20.
The Poland strike is expected to further expose faultlines in the group, which has struggled to find common ground on Russia's invasion of its neighbour, coming together to condemn the war's effects but remaining divided on apportioning blame.
The summit has shown that even Russia's allies have limited patience with a conflict that has inflated food and energy prices worldwide and raised the spectre of nuclear war.
In a draft communique, Russia was forced to agree that the "war in Ukraine" -- which Moscow refuses to call a war -- has "adversely impacted the global economy".
It also agreed that "the use or threat of use of nuclear weapons" was "inadmissible", after months of President Vladimir Putin making such threats.
But Russia's G20 allies China, India and South Africa have so far refrained from publicly criticising Putin's war, and the draft joint statement is replete with diplomatic fudges and linguistic gymnastics.
Putin shunned the gathering, instead sending his pugnacious Foreign Minister Sergei Lavrov, who left the summit Tuesday night, skipping the final day of talks.
The United States and its allies have used the summit to broaden the coalition against Russia's invasion and scotch Moscow's claims of a war of East versus West.
Host Indonesia, meanwhile, has walked a tightrope, keen to end its G20 presidency with the relative triumph of a joint statement agreed by the fractured grouping.
It has declined to criticise Russia, and invited Zelensky to address the summit with a speech Tuesday in which the Ukrainian leader urged his counterparts to end the war and "save thousands of lives".
Taking leaders on a walkabout at a mangrove on Wednesday, Indonesian President Joko Widodo brushed aside questions about the conflict.
"The G20 is an economic forum, a financial forum, and diplomat forum, not a political forum. So here we talk about the economy," he said.
Deccan Herald is on WhatsApp Channels | Join now for Breaking News & Editor's Picks