Russia said on Monday it had shot down a Ukrainian drone close to one of its air bases for long-range bombers deep inside its own territory and that three Russian air force personnel had been killed in the incident.

The drone was allegedly flying near Russia's Engels air base where long-range strategic bombers that may have been used to target Ukrainian cities and infrastructure are based. No planes were damaged in the incident, Russia defense ministry said in a statement carried by Russian news agencies.

The air base, one of two strategic bomber bases housing Russia's air-delivered nuclear capability, is located near the city of Saratov, about 730 km (450 miles) southeast of Moscow and hundreds of kilometres from the frontlines in Ukraine.

Putin claims Moscow ready for Ukraine talks 

In an interview aired on Sunday, President Vladimir Putin told Rossiya 1 state television that Russia is ready to negotiate with all parties involved in the conflict in Ukraine but Kyiv and its Western backers have refused to engage in talks.

"We are ready to negotiate with everyone involved about acceptable solutions, but that is up to them - we are not the ones refusing to negotiate, they are,”— something the Kremlin has repeatedly stated in recent months.

Putin also said he believes the Kremlin was “acting in the right direction."

“We're defending our national interests, the interests of our citizens, our people,” he said.

Putin's remarks come as attacks on Ukraine continue. A country-wide air raid alert was announced twice on Sunday alone, and three missiles in the afternoon hit the city of Kramatorsk in the partially occupied Donetsk region, local officials reported.

The Ukrainian military said early on Monday dozens of towns in the Luhansk, Donetsk, Kharkiv, Kherson and Zaporizhzia regions had been shelled.

"In the Kherson direction, the enemy continues artillery shelling of populated areas along the right bank of the Dnipro River," the Ukrainian military said.

There will be peace if the Americans want peace: Hungarian PM

“Ukraine can only continue fighting as long as the U.S. is supporting them with money and weapons,” said Hungarian Prime Minister Viktor Orbán in his interview with Magyar Nemzet last week, adding that “there will be peace if the Americans want peace”.

The U.S. has dismissed Putin's comments about him being “open to talks” as posturing, due to continued Russian attacks on Ukraine.

(With input from agencies)