KYIV, Ukraine (AFP) — Ukraine was hit with "massive" Russian missile strikes across the country on Thursday, including in the capital Kyiv, the military said.

"December 29. Massive missiles attack… The enemy is attacking Ukraine from various directions with air and sea-based cruise missiles from strategic aircraft and ships," Ukraine's air force said on social media.

According to presidential aide Mykhaylo Podolyak, more than 120 missiles were fired.

After a series of battlefield setbacks and lost territory this summer and autumn, Moscow has stepped up its aerial campaign repeatedly targeting Ukraine's energy infrastructure with drones and missiles.

On Thursday morning, blasts were reported in cities across the country, including the capital Kyiv where mayor Vitali Klitschko warned of potential power cuts and called on residents to stock up on water.

Two private houses were hit by fragments of downed missiles in the east of the capital while an "industrial enterprise" and a playground were damaged in the city's southwest, the Kyiv city military administration said.

There was a "series of explosions" in Ukraine's second city Kharkiv in the east, mayor Igor Terekhov said.

Explosions were also reported in the western city of Lviv, mayor Andryi Sadovyi said.

Lviv region governor Maksim Kozytski said air defense was operating and called on residents to stay in shelters.

About 90 percent of the city is without power after the strikes, according to its mayor.

No hurry

Meanwhile, Russia's foreign minister said Wednesday he was convinced that Moscow would achieve its goals in Ukraine.

"I am convinced that thanks to our perseverance, patience and determination, we will defend the noble goals that are vital for our people and our country," Russia's top diplomat Sergei Lavrov said in an interview broadcast on national television Wednesday.

He reiterated Moscow's stance that for talks to resume Kyiv should recognize the annexation by Russia of four Ukrainian regions.

"Our absolute priority is four new Russian regions," Lavrov said. "They should become free from the threat of Nazification that they have faced for many years."

Russia does not currently control the regions of Donetsk, Lugansk, Kherson and Zaporizhzhia in full, and Lavrov confirmed that was Moscow's ultimate goal.

Lavrov said that while Moscow wanted the conflict to be over, Russia would take its time to achieve its goals on the battlefield.

"We are in no hurry," he said.