KYIV (Reuters) -Ukraine on Wednesday reported some success in fighting near the Russian-occupied eastern city of Bakhmut as its troops press on with a counteroffensive against Moscow's forces.

Heavy fighting and Russian drone strikes on Ukrainian cities have continued while President Volodymyr Zelenskiy is in Vilnius for meetings with NATO leaders who are holding a summit in the Lithuanian capital.

"The (Ukrainian) Defense Forces continue to conduct offensive operations north and south of the city of Bakhmut," Andriy Kovaliov, a spokesperson for the armed forces general staff, said.

"In the directions of Bila Hora-Andriivka and Bila Hora-Kurdyumivka, they have had success in some places," he said, referring to sectors of the frontline south of Bakhmut.

He said Russian forces were putting up strong resistance, moving units and troops, and deploying reserves as Ukraine presses on with the counteroffensive launched in May. He did not say how much ground Ukraine had gained in the latest combat.

Russia captured Bakhmut in May after months of intense fighting that devastated the city, seen by Moscow as a stepping stone to further advances following its full-scale invasion in February 2022.

Russian accounts from the front line on Tuesday spoke of clashes but referred to a successful defence of areas near Bakhmut.

Reuters could not verify the situation on the battlefield, and Russia has not acknowledged Ukrainian gains.

Russia also launched kamikaze drone attacks on Kyiv overnight, and attacked the capital and the southern port of Odesa the previous night.

The Institute for the Study of War (ISW), an American nonprofit research group and think tank, said strikes on port infrastructure were "likely intended to discourage NATO members from providing more military aid to Ukraine."

(Reporting by Anna Pruchnicka in Gdansk and Kyiv newsroom; Editing by Timothy Heritage)