KYIV, June 14 - President Volodymyr Zelenskyy said on Saturday that Ukrainian forces had recaptured Andriivka village in northeastern Sumy region as part of a drive to expel Russian forces from the area, Reuters reported.

Zelenskyy has in the past week focused on what he describes as a drive to push out Russian forces from the Sumy region, with border areas gripped by heavy fighting. He says Russia has amassed 53,000 troops in the area.

"Based on recent developments, our special thanks go to the soldiers of the 225th Separate Assault Regiment -- for offensive operations in the Sumy region and the liberation, in particular, of Andriivka," Zelenskyy said in his nightly video address.

Zelenskyy also noted "successful actions" near Pokrovsk, for months a focus of Russian attacks in their slow advance on the eastern front, and "strong results" near Kupiansk, an area in northeastern Ukraine that has come under heavy Russian pressure.

In remarks released for publication earlier on Saturday, Zelenskyy said Ukrainian forces had stopped Russian troops advancing in Sumy region and were battling to regain control along the border.

"We are levelling the position. The fighting there is along the border. You should understand that the enemy has been stopped there. And the maximum depth at which the fighting takes place is 7 km (4 miles) from the border," Zelenskyy said.

Reuters could not verify the battlefield reports.

Russia's troops have been focusing their assaults in the eastern Donetsk region, with Pokrovsk a particular target.

But since the start of the month, they have intensified their attacks in the northeast, announcing plans to create a so-called 'buffer zone' in the Sumy and Kharkiv regions.

Russia's Defence Ministry said on Saturday that its forces had seized the village of Zelenyi Kut, southwest of Pokrovsk.

The Russian war in Ukraine is in its fourth year, but it has intensified in recent weeks.

Ukraine conducted an audacious drone attack this month that took out multiple aircraft inside Russia and also hit the bridge connecting Russia to the annexed Crimean peninsula using underwater explosives.

Moscow ramped up its air assaults after the attack.

Zelenskiy said Ukrainian troops had maintained defensive lines along more than 1,000 km of the frontline. He also dismissed Moscow's claims that Russian troops had crossed into the central Ukrainian region of Dnipropetrovsk.

Zelenskiy said that Russia was sending small assault groups "to get one foot on the administrative border" and make a picture or a video, but these attacks were repelled.

The popular Ukrainian military blog DeepState, which relies on open-source data, said Ukrainian troops had repelled a Russian attack in the area, but also reported Russian advances in other areas, including Pokrovsk.

Dnipropetrovsk borders three regions that are partially occupied by Russia – Donetsk, Kherson and Zaporizhzhia. Russia now controls about one-fifth of Ukrainian territory.

Zelenskiy acknowledged that Ukraine was unable to regain all of its territory by military force and reiterated his pleas for stronger sanctions to force Moscow into talks to end the war.

Two rounds of peace talks in Istanbul produced few results that could lead to a ceasefire and a broader peace deal. The two sides agreed only to exchange prisoners of war.

Several swaps have already been conducted this month, and Zelenskiy said he expected them to continue until June 20 or 21. (rt/ez)