Negotiations between Kyiv and its allies over Ukraine's demands for long-range missiles, which it says are meant to prevent Moscow from destroying Ukrainian cities, are proceeding apace, an adviser to President Volodymyr Zelensky, Mykhailo Podolyak, said.

"In order to drastically reduce Russia's key weapons, we need missiles that will destroy their stockpiles," Podolyak told Ukrainian television.

He added that there are more than 100 artillery depots in Crimea, which was occupied by Russia.

"First of all, that's why the negotiations are already underway. Secondly, the negotiations are progressing at an accelerated pace," he added, but did not go into details.

Speaking separately, Zelensky said Ukraine wanted to prevent Russian attacks on Ukrainian urban areas and civilians.

"Ukraine needs long-range missiles to deprive the occupier of the ability to place its missile launchers somewhere far from the front line and destroy Ukrainian cities," he said in his evening video message. Zelensky added that Ukraine needs American-made ATAKMS missiles, which have a range of 297 kilometers. Washington has so far refused to send those weapons.

Ukraine, which has been promised Western tanks, has also requested fighter jets to repel Russian and pro-Russian forces, which are slowly advancing in some parts of the front line.

White House deputy national security adviser John Finner said Thursday that the United States would discuss the idea of ​​sending the planes "carefully" with Kyiv and its allies. Germany's defense minister ruled out sending fighter jets to Ukraine this week.