WASHINGTON - The United States is not enabling or encouraging Ukraine to strike beyond its borders, US Secretary of State Antony Blinken said on Tuesday, after Ukraine demonstrated an apparent new ability to penetrate hundreds of kilometres into Russian air space with attacks on air bases.

Moscow said attacks on Monday killed three of its servicemen and wounded four, as well as damaging two warplanes.

On Tuesday, a third Russian airfield in Kursk, which lies closer to Ukraine, was set ablaze in another drone strike.

“We have neither encouraged nor enabled the Ukrainians to strike inside of Russia,” Secretary of State Antony Blinken told reporters.

“But the important thing is to understand what Ukrainians are living through every day with the ongoing Russian aggression,” he said, accusing Russia of “weaponising winter” through attacks on civilian infrastructure.

Mr Blinken vowed “our determination to make sure that they have in their hands – along with many other partners around the world – the equipment that they need to defend themselves, to defend their territory, to defend their freedom.”

Experts believe Ukraine penetrated Russian airspace with simple Soviet-era drones and not any of the billions of dollars in military assistance given by Western powers since Moscow’s Feb 24 invasion.

Speaking next to Mr Blinken after talks with their Australian counterparts, US Defence Secretary Lloyd Austin said Washington was not stopping Ukraine from developing long-range missiles on its own.

“The short answer is no. We’re absolutely not doing that,” he said. “We are not working to prevent Ukraine from developing their own capability.”

“We are not enabling Ukraine to strike beyond its borders. We are not encouraging Ukraine to strike beyond its borders,” US State Department spokesman Ned Price told reporters, adding that there was no confirmation the strikes were carried out by Ukraine.

The government in Kyiv did not directly claim responsibility for the strikes, but nonetheless celebrated them.

Mr Price said the United States has not provided Ukraine with weapons that are to be used within Russia.

“We have been very clear that these are defensive supplies,” Mr Price said.

In the strike on Tuesday, officials in the Russian city of Kursk, around 90km north of the Ukraine border, released pictures of black smoke above an airfield. The governor said an oil storage tank had gone up in flames but there were no casualties.

The day before Russia said it had been hit hundreds of kilometres from Ukraine by what it said were Soviet-era drones - at Engels air base, home to Russia’s strategic bomber fleet, and in Ryazan, a few hours’ drive from Moscow.

It was not the first time Russia had accused Ukraine of using drones for attacks inside its borders since beginning its war against Ukraine in late February.

Russia responded with what it called a “massive strike on Ukraine’s military control system”, though it did not identify any specific military targets for what Ukraine called Moscow’s latest strikes on civilian infrastructure.

Missiles across Ukraine destroyed homes and knocked out power, but the impact seemed less severe than barrages last month that pitched millions of Ukrainians into darkness and cold.

Washington’s goal is to regularly convene allies from Europe and around the world to provide Ukraine assistance on its energy needs, Mr Price said.

Moscow claims a military justification for attacks on Ukraine’s civil infrastructure. Kyiv says the strikes are intended to hurt civilians, a war crime. REUTERS