The Russian foreign ministry said on Friday that a Molotov cocktail had been thrown at the country's consulate in the Ukrainian city of Lviv and that it had protested against the attack, which it described as an act of terrorism.
The ministry summoned a Ukrainian official and demanded apologies from his country's authorities.
Ukrainian police in Lviv said they had launched an investigation into the incident, which they referred to as hooliganism.
The incident comes as Russia builds up troops near the border with Ukraine that has sparked fears of an invasion.
The Kremlin also said on Friday that it expects the US to respond next month to its request for security guarantees that prevent Nato expansion to Ukraine.
The Russian president Vladimir Putin had urged the west to meet the demand, accusing the US and its allies of maintaining a military presence on the threshold of our home Moscow submitted draft security documents last week demanding that Nato denies membership to Ukraine and other former Soviet countries and roll back the alliance's military deployments in central and eastern Europe.
To discuss de-escalation, we expect our opponents in Washington to provide specific answers to our proposals in January, according to a spokesman for Kremlin Dmitry Peskov, during a Friday conference call with reporters.
In a video call earlier this month, the US president, Joe Biden, told Putin that Russia would face serious consequences if it attacked Ukraine.
Moscow has denied it plans to launch an attack, but has described Nato expansion and weapons deployment in Ukraine as a red line.
The US and its allies have said they won't give Russia the kind of guarantee on Ukraine that Putin wants. One of the key principles of Nato is that membership is open to any qualifying country. The US officials are meeting with European allies in advance of the Geneva talks.
Ukrainian foreign minister Dmytro Kuleba said on Friday that his country must be part of any Nato security talks with Russia.
He said that Ukraine should be part of the security consultations on the matter because of the Euro-Atlantic security in Ukraine. We strongly support the idea of the US, the EU, Nato talking to Russia as long as the primary topic is ending the international armed conflict, Russia's war on Ukraine. Peskov rejected western concerns about the Russian troop buildup. He said the country was entitled to deploy its military wherever it considers necessary on its territory, and presented the recent movements as a defensive response to the provocations from the west.
Whatever Russia does with its troops, it does it on its own territory, and we can't allow anyone to challenge that right, he said. Russia takes certain actions to move and redeploy its forces on its territory in response to unfriendly moves by our opponents from Nato, the US and some European countries that have made unambiguous manouvres near our borders, such as reconnaissance flights and deployment of warships. It causes our deep concern and forces us to take certain measures to ensure our security. Russia annexed Crimea in 2014 and threw its support behind a separatist rebellion in eastern Ukraine. More than 14,000 people have been killed in the fighting, which has also devastated Ukraine's industrial heartland known as the Donbas.
Putin said earlier this week that Russia would have to take appropriate military-technical measures if the west continued its aggressive course.
He hailed another successful test of a new hypersonic weapon on Friday. He said that a salvo of Zircon cruise missiles had been fired flawlessly. This is a big event for the country and a major step in strengthening Russia's security and enhancing its defence capability. The missile is expected to enter service with the Russian navy next year and arm its cruisers, frigates and submarines in a series of tests by Zircon, which Putin has said is capable of flying at nine times the speed of sound to a range of more than 1,000 kilometres 600 miles.
Putin said last month that Nato could use Ukrainian territory to deploy missiles that would be able to reach Moscow in just five minutes, and that Zircon would give Russia a comparable capability.
He said that it would need just five minutes to reach those who issue orders.