Kyiv said on Friday Ukrainian experts had started work at the site where a missile killed two people in southeastern Poland, as the countries discuss what role Ukraine may play in an investigation into the incident.
Poland and other Western states have said the missile that landed in Przewodow, a village near the border with Ukraine, was a Ukrainian air defence missile that went astray in pursuit of a Russian missile.
Kyiv denied this, saying it has evidence of a "Russian trace" in the blast, and demanded access to the site and a role in the investigation into the cause of the explosion.
Ukrainian Foreign Minister Dmytro Kuleba wrote on Twitter that Ukrainian experts were already working at the site, but did not mention Kyiv's demand to take part in the investigation.
"I am grateful to the Polish side for granting (the experts) access. We will continue our cooperation in an open and constructive manner, as closest friends do," he said.
Warsaw had said Ukrainian officials would be able to see the site of the blast. But it also said participation in the investigation and access to documentation required the agreement of the countries leading the probe, Poland and the United States, and must be in line with international law and treaties.
"Yesterday we were in very intensive contact with the Ukrainian side," Polish deputy justice minister Sebastian Kaleta told the wp.pl news website.
"The prosecutors of the relevant units of the national prosecutor's office or the regional prosecutor's office are in contact with representatives of the general prosecutor's office of Ukraine. There were high-level talks."
He gave no details of the outcome of the discussions.
Warsaw, Kyiv and their Western allies have said that ultimate responsibility for the explosion lies with Russia, which invaded Ukraine in February and has been pounding Ukrainian energy facilities with missiles.
The funerals of the two agricultural workers killed in the blast will take place on Saturday and Sunday, local authorities said.
(Reporting by Alan Charlish and Pawel Florkiewicz in Warsaw, Agnieszka Pikulicka-Wilczewska in Przewodow and Max Hunder in Kyiv, Editing by Timothy Heritage)
