The US president, meanwhile, held a video conference with France, Germany and Britain to discuss a ban on Russian oil.
Recipients were signatories to EU member states and major non-European powers, such as Australia, Canada and Japan.
The first round of talks between the Russian and Ukrainian delegations took place on the Ukrainian-Belarusian border, but to no avail.
Ukraine is not part of NATO, and according to Jens Stoltenberg, there are no NATO troops there.
Turkish President Recep Tayyip Erdogan has condemned Russia’s attack on Ukraine, calling it a “major blow” to regional peace.
Ukraine is located on the northern border of Europe, bordering Russia.