Kyiv (Ukraine) (AFP) - Russia on Monday claimed the capture of another village in Ukraine's eastern Donetsk region, the latest in a string of gains ahead of a major Ukraine summit in Switzerland.

Dozens of world leaders and top diplomats are to convene for a meeting at the weekend that President Volodymyr Zelensky hopes will rally global support behind Kyiv as it struggles more than two years into Russia's invasion. 

Zelensky has ruled out direct talks with Russian President Vladimir Putin and is keen to win over more non-Western countries, including those who maintain close ties with Moscow.

After almost a year of stalemate, Ukraine has been forced to abandon dozens of front-line settlements this spring, with Russian troops holding a significant advantage in manpower and resources.

Russia's defence ministry said Monday that its forces "continued to advance into the depths of the enemy's defence and liberated the settlement of Staromaiorske", located southwest of the Russian-held city of Donetsk.

The loss of the village is a symbolic blow to Kyiv, as it is one of the few Ukraine managed to recapture last year in a largely lacklustre counter-offensive.

Staromaiorske is on the southern front of the Donetsk region, one of the four regions Moscow claimed to have annexed in 2022 and where some of the fiercest fighting is now taking place.

Putin told an economic forum last week that Russia had seized 47 Ukrainian towns and villages so far this year.

That includes gains in the northeastern Kharkiv region where Moscow launched a major ground assault last month, causing thousands of Ukrainians to evacuate and further stretching Kyiv's forces.

US President Joe Biden's national security adviser, Jake Sullivan, said Sunday that Russia's advance on the Kharkiv border region had "stalled out" after Washington partially lifted restrictions on using US-donated weapons to strike inside Russia.

90 countries

In a diplomatic setback for Kyiv, Biden confirmed last week that he would not be attending the June 15-16 summit at the Burgenstock Resort, which overlooks Lake Lucerne in central Switzerland.

Vice President Kamala Harris will instead represent Ukraine's most important military and financial backer.

Zelensky had also hoped to secure high-level attendance from some of Moscow's allies, principally China.

Beijing has criticised the gathering and said it would be "difficult" to attend without Russia's participation.

The Swiss presidency said Monday that 90 countries had confirmed their attendance at the summit, which would follow a G7 summit in Italy.

The initiative is unlikely to produce a significant breakthrough, but Ukraine hopes it will build international support for its position that Russia should not be able to crystallise territorial gains through its invasion. 

The gathering will also allow Kyiv to lobby for more military, financial and diplomatic aid.

The Kremlin has blasted any talks about the conflict without its participation as "absurd".

'Obsession'

On the battlefield, Russia has now shifted its focus to two strategic towns in the Donetsk region, Ukrainian soldiers fighting there told AFP at the weekend.

"The fiercest fighting is taking place in this area: Pokrovsk and Chasiv Yar. This is the sector they really want. This is their obsession," said Oleksandr, a 36-year-old tank сrew member.

Russian forces have been attacking the hilltop town of Chasiv Yar for months.

Its capture would be a strategic blow to Ukraine and could leave it vulnerable to further Russian advances.

Another Ukrainian soldier, Danylo Madiar, 33, said it "had become very difficult to hold this front line" with many losses.

Zelensky said Monday that the situation in the Donetsk region was "the most difficult" across the entire front line.

Russia also continued a campaign of aerial attacks on Kharkiv city, Ukraine's second largest, on Monday with a strike that injured at least seven people, officials said.

"There were three attacks on the city with guided aerial bombs," Mayor Igor Terekhov said in a post on Telegram.

Earlier in the day one person was reported killed and two wounded by Russian fire on the village of Dergachi, to the northwest of the city.

Ukrainian forces separately claimed to have struck an advanced Russian air defence system overnight on the Crimean peninsula, which Moscow annexed in 2014. 

The general staff said Ukraine had hit an S-400 air defence system near the town of Dzhankoy and also targeted two S-300 systems near Chornomorske and Yevpatoriya.

There was no immediate comment from Moscow on the alleged strikes and AFP could not independently verify the claims.

Seven people were also injured in Russia's Belgorod border region, four after a mine blast and three by a Ukrainian aerial attack, the governor said.