Moscow will retaliate against Western sanctions targeting Russia's aviation industry amid ongoing tensions, Kremlin spokesman Dmitry Peskov said on Monday.

"The guiding principle will be reciprocity, and our own interests will be at the forefront of that," he told reporters on a conference call.

His comments came as the European Union closed airspace to Russian flights and the bloc's historic move on Sunday to supply weapons to Ukraine.

European Commission President Ursula von der Leyen on Sunday evening proposed "shutting down the EU airspace for Russians", a prohibition on "all Russian-owned, Russian-registered or Russian-controlled aircraft". She added that these aircraft will not be able to land in, take off or overfly the EU territory.

Before that, several EU states such as Sweden, Denmark, Belgium, France, the Netherlands, Italy, Austria had already announced bans of Russian flights from their airspace.

Russia had already closed its airspace to flights from Bulgaria, Poland and the Czech Republic in response to "unfriendly actions of the aviation authorities" of the mentioned countries.

On Sunday, the EU also said it will fund the purchase and delivery of some $500 million worth of weapons to Ukraine, making it the first time for the bloc to do so through its off-budget European Peace Facility instrument. EU treaties prohibit the bloc from using its normal budget to fund operations.

"For the first time ever, the EU will finance the purchase and delivery of weapons and other equipment to a country that is under attack," said von der Leyen.

In a statement before an emergency virtual meeting of foreign ministers of the 27 EU member states on Sunday, EU foreign policy chief Josep Borrell said they are doing this as "this war requires our engagement in order to support the Ukrainian army－because we live in unprecedented times".

The EU also announced it would ban Russia Today, Sputnik and their subsidiaries from broadcasting in the EU.

Von der Leyen also said the EU will also introduce restrictive measures to punish Belarus for helping Russia.

EU membership

In response to calls for a speedy path to Ukraine's EU membership, von der Leyen expressed that "they are one of us and we want them in".

"We have a process with Ukraine that is, for example, integrating the Ukrainian market into the single market," she told Euronews in an interview on Sunday.

Ukrainian President Volodymyr Zelensky wrote in a tweet on Sunday that he spoke with von der Leyen about his country's EU membership, as well as defense capabilities and macro-financial assistance.

On Sunday, German Chancellor Olaf Scholz took another major step by announcing a huge boost in Germany's military spending after a complete reversal of its long-standing policy of not sending arms to conflict zones.

Scholz told an emergency session of the German parliament that his government would set up a special fund of 100 billion euros ($112 billion) to swiftly upgrade its armed forces and that Germany will adhere to the NATO goal of spending 2 percent of its GDP on defense in the future.

Agencies contributed to this story.