Poland missile attack: US President Joe Biden says 'unlikely' that missile fired from Russia

Poland said early Wednesday that a Russian-made missile fell in the country's east, killing two people, though U.S. President Joe Biden said it was "unlikely" it was fired from Russia.

The blast, which Ukrainian President Volodymr Zelenskyy decried as "a very significant escalation," prompted Biden to call an emergency meeting of G-7 and NATO leaders.

A deliberate, hostile attack on NATO member Poland could trigger a collective military response by the alliance.

Also Read: NATO, world leaders to meet as Poland claims Russian-made rocket kills two; Moscow denies

But key questions around the circumstances of the missile launch remained amid the confusion caused by a blistering series of Russian airstrikes across the nearby border in Ukraine, none larger than who fired it.

Russia denied any involvement in the Poland blast.

Three U.S. Officials said preliminary assessments suggested the missile was fired by Ukrainian forces at an incoming Russian one amid the crushing salvo against Ukraine's electrical infrastructure Tuesday.

The officials spoke on condition of anonymity because they were not authorized to discuss the matter publicly.

That assessment and Biden's comments at the Group of 20 summit in Indonesia contradict information earlier Tuesday from a senior U.S. Intelligence official who told the AP that Russian missiles crossed into Poland.

The Polish government said it was investigating and raising its level of military preparedness. Biden pledged support for Poland's investigation.

A statement from the Polish Foreign Ministry identified the weapon as being made in Russia.

President Andrzej Duda was more cautious, saying that it was "most probably" Russian-made but that its origins were still being verified.

"We are acting with calm," Duda said. "This is a difficult situation."

Biden's decision to convene the emergency meeting upended schedules for the final day of the Group of 20 meeting in Indonesia.

Biden, who was awakened overnight by staff with the news of the missile while attending the summit, called Polish President Andrzej Duda to express his condolences. On Twitter, Biden promised "full U.S support for and assistance with Poland's investigation," and "reaffirmed the United States" ironclad commitment to NATO.

Meanwhile, NATO Secretary-General Jens Stoltenberg called the meeting of the alliance's envoys in Brussels.

The U.N. Security Council also planned to meet Wednesday for a previously scheduled briefing on the situation in Ukraine.