Moscow urged to annex Kherson, claims Kyiv bombed Russia town

Pro-Kremlin authorities in Ukraine's Kherson on Wednesday urged President Vladimir Putin to annex the region, as Moscow accused Kyiv of shelling a Russian city in the latest flashpoint of their bloody war.

One person was killed and three injured in the shelling of Belgorod, according to governor Vyacheslav Gladkov, who said it was "the most difficult situation facing the border region since Russia sent its troops into Ukraine 11 weeks ago.

With war raging, fears of broader international implications swelled as gas supplies to energy-starved Europe were disrupted by a halt in Russian gas flows through Ukraine.

The stoppage caused supplies to plunge by 25 percent in Germany, which is dependent on Russia for its energy and has rejected an immediate full embargo on Russian gas.

The developments came as Ukraine said its military was holding its own and pushing Russian troops back from the country's second city Kharkiv in the northeast.

Russia has focused on eastern and southern Ukraine since it failed to take Kyiv in the first weeks after the February 24 invasion, and US intelligence has warned Putin is ready for a long war.

Kherson, the first major Ukrainian city to fall, is north of Crimea, which itself was annexed by Moscow in 2014.

Kirill Stremousov, deputy head of Kherson's Moscow-installed administration, said there would be a "request to make Kherson region a full subject of the Russian Federation."

But the Kremlin replied it was up to the residents of Kherson to "determine their own fate".

Ukrainian presidential aide Mykhaylo Podolyak said Kyiv's forces would liberate Kherson and "the invaders may ask to join even Mars or Jupiter."

While President Volodymyr Zelensky framed his nation's conflict as a "war against tyranny," Ukraine's fierce fight back has come with a heavy cost.

In a rare release of battle casualty figures, Ukraine's National Guard, which falls under the interior ministry, said Wednesday that 561 of its members have been killed and nearly 1,700 wounded since the invasion began.

Neither the defence ministry in Kyiv nor its counterpart in Moscow have provided official death counts, but in mid-April Zelensky said between 2,500 and 3,000 Ukrainian soldiers had been killed.