Moscow: Russia is consistently building up its navy, with 30 ships set to join the country's fleet in 2023, Russian President Vladimir Putin said on Sunday amid the ongoing war with Ukraine.

"Today, Russia is implementing the tasks of a large-scale maritime policy with confidence, consistently building up the power of its fleet. This year alone, 30 ships of different types will join it," Putin said at the parade in honour of Navy Dayas reported by Sputnik.

The ships put on combat duty include the Mercury missile corvette, on which the St. George naval flag has been hoisted "as a sign of the inviolability of [Russian] naval traditions, a symbol of courage, bravery and firmness of military sailors," the Russian leader stated.

"These qualities are being fully manifested today," Putin said, adding that the Russian navy had always been an inviolable guardian of the country's frontiers.

Meanwhile, Russia on Sunday accused Ukraine of carrying out a drone attack on Moscow city which damaged two buildings and even forced authorities to shut down the city's airport temporarily.

A drone was shot down over the Odintsovo district, west of the city centre, and two others were neutralised but crashed into offices, Russia's defence ministry was quoted as saying by BBC.

One person was injured due to the blast, reports TASS news agency.

Ukraine tried to carry an attack on Crimea overnight using 25 drones, all of which were destroyed, the Russian Defense Ministry said on Sunday morning.

"Tonight, an attempt by the Kiev regime to carry out a terrorist attack using twenty-five aircraft-type unmanned aerial vehicles [UAVs] on objects on the territory of the Crimean peninsula was thwarted," the ministry said in a statement as quoted by Sputnik.