- Nato, Poland say missile likely from Ukraine air defence
- Moscow says missile was Ukrainian air defence S-300
- Zelenskiy demurs, says 'no doubt' missile not Ukrainian
- Nato says Russia bears ultimate responsibility
Nevertheless, Nato's chief said that Moscow, not Kyiv, was still to blame for starting the war in the first place with its February invasion and launching scores of missiles on Tuesday that triggered Ukrainian defences.
"This is not Ukraine's fault. Russia bears ultimate responsibility as it continues its illegal war against Ukraine," Nato Secretary-General Jens Stoltenberg told reporters in Brussels.
Nato ambassadors held emergency talks to respond to Tuesday's blast that killed two people at a grain facility in Poland near the Ukrainian border, the war's first deadly extension into the territory of the Western alliance.
"From the information that we and our allies have, it was an S-300 rocket made in the Soviet Union, an old rocket and there is no evidence that it was launched by the Russian side," Polish President Andrzej Duda said. "It is highly probable that it was fired by Ukrainian anti-aircraft defence."
Stoltenberg also said it was likely to have been a Ukrainian air defence missile. Earlier, US President Joe Biden had said the trajectories suggested the missile was unlikely to have been unleashed from Russia.
Ukrainian President Volodymyr Zelenskiy demurred, saying "I have no doubt that it was not our missile", Ukrainian media reported on Wednesday. He said he based his conclusion on reports from Ukraine's military which he "cannot but trust".
He gave no evidence for his position, while saying he believed Ukraine should already have been given access to the site of the explosion as Kyiv had the right to be there.
The incident occurred while Russia was firing scores of missiles at cities across Ukraine, targeting its energy grid and worsening power blackouts for millions, in what Kyiv says was the most intense volley of such strikes of the nine-month war.
Kyiv says it shot down most of the incoming Russian missiles with its own air defence systems. Ukraine's Volyn region, just across the border from Poland, was one of the many Ukraine says was targeted by Russia's countrywide fusillade.
The Russian Defence Ministry said none of its missiles had struck closer than 35 km (20 miles) from the Polish border, and that photos of the wreckage in Poland showed elements of a Ukrainian S-300 air defence missile.
The Kremlin said on Wednesday some countries had made "baseless statements" about the incident, after having accused Poland of an "absolutely hysterical" reaction on Tuesday, but that Washington had been comparatively restrained.
Zelenskiy also said Kyiv had received no offer from Moscow to start peace talks. Kremlin spokesman Dmitry Peskov said earlier this week Ukraine was not interested in such talks.
Zelenskiy's top adviser Mykhailo Podoloyak dismissed the notion of talks. "Putin's Russia is a key threat to the global world. Ukraine is trying to restrain Russian outrages, stop the escalation and growth of the war. Do not look for 'compromises' between the killer-country (Russia) and the civilized world. This is the path to a global tragedy," Podolyak tweeted.
The news that Western officials had concluded the missile was Ukrainian brought some relief to the inhabitants of the Polish village hit by the missile, with some saying they had feared being dragged into the war.
"Everyone has in the back of the head that we are right near the border and that an armed conflict with Russia would expose us directly," said Grzegorz Drewnik, the mayor of Dolhobyczow, the municipality to which Przewodow belongs.
"If this is a mistake of the Ukrainians, there should be no major consequences, but I'm not an expert here."
Some Western leaders at a summit of the G20 big economies in Indonesia suggested that whoever fired the missile, Russia and President Vladimir Putin would ultimately be held responsible for an incident arising from its invasion.
G20 leaders issued a closing declaration saying "most members strongly condemned the war in Ukraine", although it acknowledged that "there were other views".
Moscow carried out Tuesday's missile volley just days after abandoning the southern city of Kherson, the only regional capital it had captured since the invasion.
The barrage echoed a pattern of Moscow lashing out with longer-range missile salvoes after losses on the battlefield to a continuing Ukrainian counter-offensive in the east and south.
However, the top US general played down the odds of any near-term, outright military victory by Ukraine, cautioning that Russia still had significant combat power inside Ukraine despite a string of setbacks.
"Politically, there may be a political solution where, politically, the Russians withdraw. That's possible," Army General Mark Milley, chairman of the Joint Chiefs of Staff, told a news conference in Washington.
Russia "right now is on its back", Milley added.