There have been several disputes over planes being shot down over eastern Ukraine in recent days.
On Wednesday evening, a Ukrainian fighter jet was shot down by an air-to-air missile from a Russian plane, Ukrainian authorities said Thursday, adding to what Kiev says is mounting evidence that Moscow is directly supporting the separatist insurgents.
Ukrainian Security and Defense Council spokesman Andrei Lysenko said the pilot of the Sukhoi-25 jet hit by the air-to-air missile was forced to eject as his jet was shot down.
Pro-Russia rebels also claimed responsibility for strikes Wednesday against two Ukrainian Sukhoi-25 jets.
“Very serious clashes are ongoing in the region where the Boeing crashed. Nonstop gunfire is under way there,” Andrei Purgin, the militia’s first deputy prime minister, told Interfax.
Almost immediately after the crash, Moscow asked for its investigators to be granted access to the crash site, which is controlled by the Russia-backed separatists in the region who reportedly blocked access by Ukraine authorities.
Mr. Putin, meanwhile, vowed that Russian investigators would provide an objective report.
“We must to our best to see to it that the objective picture is part of the public domain here, in Ukraine and in the rest of the world,” he said.
He added that he already had ordered agencies “to offer all possible assistance in the investigation of this crime,” according to ITAR-Tass.
• This article is based in part on wire service reports.