Sawt Falasteen - Ukraine says has withdrawn troops in parts of Kharkiv region

President Volodymyr Zelensky cancelled planned trips abroad over the fresh offensive and the military was sending more troops to Kharkiv to hold back Russian advances, Kyiv said.

Details of the withdrawal emerged as US Secretary of State Antony Blinken was on an unannounced visit to Kyiv where President Volodymyr Zelensky urged him to speed up US supplies of weapons.

Moscow launched a surprise major ground assault on the Kharkiv region last week as it seeks to advance across the battlefield with Kyiv struggling for arms and manpower.

"In certain spots in Lukyantsi and Vovchansk areas, due to the fire impact and assault actions of the enemy, manoeuvres were carried out in order to save the lives of our soldiers, units were removed to advantageous positions," a military spokesman said on state television.

Authorities in Vovchansk said there was intense street-to-street fighting in the border town that before the war had an estimated population of 20,000 people.

"We are here and are evacuating people and helping them. The situation in Vovchansk is extremely difficult," police chief Oleksiy Kharkivsky said on social media.

- 'Additional forces being deployed' -

The interior ministry announced that three civilians had been killed in the Kharkiv region over the last 24 hours and that a Russian drone had wounded two policemen.

Throughout the two-year war, both sides have typically used the language of moving to more "advantageous positions" to signify retreats.

The two villages -- around 30 kilometres (18 miles) apart -- are close to the border with Russia and have been targeted in the fresh offensive.

The Ukrainian military said the situation "remains difficult" but insisted that its forces were "not allowing the Russian occupiers to gain a foothold".

Zelensky's spokesman said on social media that the president had postponed upcoming trips, including one to Spain, and reiterated that the military was rushing reinforcements to the area to prevent Russia from punching through.

"Additional forces are being deployed, and there are reserves," Zelensky's office said.

- 'Difficult' fighting in east -

Some military analysts say Moscow may be trying to force Ukraine to divert troops from other areas of the front line, such as around the strategic town of Chasiv Yar in the Donetsk region, where Russia has also been advancing.

"Donetsk and Kharkiv regions are where it is most difficult now," Zelensky said in an address on Tuesday evening.

Kyiv on Wednesday ended some emergency power blackouts -- including in the capital Kyiv and frontline region of Donetsk -- that it had introduced to deal with a drop in temperatures that strained its battered energy system.

State power operator Ukrenergo had announced a series of overnight and early morning power cuts to deal with "the cold weather amid the consequences of Russian shelling" that has destroyed swathes of Ukraine's generating facilities.

Blinken's visit came just weeks after the US Congress finally approved a $61-billion financial aid package for Ukraine following months of political wrangling, unlocking much-needed arms for the country's outgunned troops.

It began as the Russian defence ministry announced that its troops had captured two more villages in the Kharkiv region. During a meeting with Blinken, Zelensky asked for two more Patriot air defence systems to defend the border territory.

On the second day of Blinken's trip, on Wednesday, he toured a drone production centre and grain export facility.

Ukraine also launched aerial attacks on Russia, forcing the closure of two airports in the region of Tatarstan some 1,000 (620 miles) kilometres inside Russian territory.

Russian aerial defence systems intercepted and destroyed 17 drones across several border areas, as well as 10 ATACMS missiles over the annexed Crimean peninsula, the defence ministry said.

O.Salim--SF-PST