In view of the "inhumane" situation in the heavily contested port city of Mariupol, Ukrainian President Volodymyr Zelenskyy has called for more support from the West.

Either the "partners will immediately supply Ukraine with all the heavy weapons it needs," or they will support him in negotiations to end the siege, Zelensky said on Sunday night.

The Russian armed forces, which according to their own statements now controlled the entire city area except for the steelworks, gave the remaining defenders an ultimatum.

Selenskyj wants to "reduce the pressure on Mariupol and break the siege" with Western fighter jets.

The Ukrainian President admitted that finding a "military or diplomatic" solution to the situation was "extremely difficult".

American weapons arrived

Meanwhile, the first parts of the latest support package from the US have arrived in Ukraine.

This was reported by the CNN TV station at night, citing an official in the White House.

Washington on Wednesday promised Kyiv additional weapons and ammunition worth up to $800 million (€740 million), including artillery, armored vehicles and helicopters.

The new deliveries are intended to support Ukraine, especially in view of the feared large-scale Russian attack in the eastern Donbass region.

The United States has already pledged or delivered $2.5 billion worth of arms to Ukraine since Russia's war of aggression began in late February.

Russia recently sent protest notes to several Western countries, including the United States, over arms deliveries to Ukraine.

EU Commission President Ursula von der Leyen called for rapid European arms deliveries.

"For all member states, those who can should deliver quickly, because only then can Ukraine survive in its acute defensive struggle against Russia," says von der Leyen of "Bild am Sonntag" according to a preliminary report.

They do not distinguish between light and heavy weapons.

The EU also plans to embargo Russian oil and extend sanctions to Sberbank, Russia's main bank.

Threatening end of talks

According to Selinsky, killing the remaining Ukrainian forces in Mariupol would mean the final end of talks with Russia.

These had not brought any results in the past few weeks.

Russian President Vladimir Putin had said they had reached a "dead end".

Mariupol has been under siege since the first days after the Russian invasion.

In the meantime, the city in the southeast, which once had over 400,000 inhabitants, has been largely destroyed and the humanitarian situation is catastrophic.

Ultimatum to remaining defenders

The Defense Ministry in Moscow said Russian troops were in control of the "entire area of ​​the city".

Ukrainian troops were surrounded in an industrial area.

It called on the fighters to give up resistance and leave the Azovstal works site by Sunday noon: "Their only chance to save their lives is to voluntarily lay down their arms and surrender."

Zelenskyi told Ukrainian media that Ukraine must prepare for the possibility that Russia might use nuclear weapons as the conflict unfolds.

The day before he had said Russia could use nuclear or chemical weapons out of desperation at military setbacks.

Austria's Chancellor Karl Nehammer, meanwhile, told the American broadcaster NBC that Putin is "now in his own war logic".

"He thinks he's winning the war." Nehammer met Putin in Moscow on Monday.

Kyiv again target of attacks

Meanwhile, after two weeks of relative calm, Russian forces stepped up their airstrikes on Kyiv.

On Saturday they attacked, among other things, a tank factory in the Ukrainian capital.

The Russian Ministry of Defense announced on Telegram that the factory’s production buildings were destroyed during the shelling with “high-precision long-range weapons”.

Kiev Mayor Vitali Klitschko reported that one person was killed and several others were injured by the explosions.

Russian troops had already attacked an armaments complex near the capital on Friday, which, according to the website of the state-owned armaments company Ukroboronprom, produced "Neptune" rockets.

The Russian missile cruiser Moskva, which sank on Thursday, was fired at with missiles of this type, according to Ukrainian sources.

Moscow did not confirm this information and said that ammunition had exploded on board the ship.

On Saturday, the Russian Defense Ministry released a video purporting to show suspected survivors of the sinking meeting with the Navy chief.

The ministry also said it had shot down a Ukrainian transport plane carrying weapons supplied by western countries in the Odessa region.