Russian Defense Ministry official has criticized Kiev over the humanitarian situation in some Ukrainian cities warning of the rapidly declining condition.

"Unfortunately, the humanitarian situation in Ukraine is continuing to deteriorate rapidly, and in some cities it has reached catastrophic proportions," said the head of the Russian National Defense Control Center, Mikhail Mizintsev, on Saturday while speaking on the 17th day of Russia’s military operation in Ukraine.

Saying that Russian forces were observing a ceasefire previously announced in parts of Ukraine, the Russian official accused Ukrainian "nationalists" of laying mines in residential areas and destroying key infrastructure, including roads and bridges, leaving civilians with no access to electricity, water, food, and medicine.

Mizintsev added that an especially dire humanitarian situation was developing in the southeastern port city of Mariupol, accusing Ukraine's "nationalists" of trapping hundreds of thousands of people in the besieged city.

The Russian Defense Ministry official also accused Ukraine's military of holding hostage nearly 7,000 people from 16 foreign countries and crews from more than 50 foreign vessels, saying, "Hundreds of thousands of people, including foreigners, are being forcibly held by [Ukrainian] nationalists."

On February 24, Russian President Vladimir Putin announced a “special military operation” aimed at “demilitarization” of the Donetsk and Lugansk regions in eastern Ukraine. In 2014, the two regions declared themselves new republics, refusing to recognize Ukraine’s Western-backed government.

Announcing the operation, Putin said the mission was aimed at “defending people who for eight years are suffering persecution and genocide by the Kiev regime.”

On Day 16th of the operation, the Russian military said it was encircling the capital Kiev, the city of Kharkiv in the east, Sumy in northeast, and Mariupol.

The Russian military is, meanwhile, setting up safe passages for locals to leave the cities.

Russia says it will halt the military operation instantly if Kiev meets Moscow’s list of conditions. Moscow has specified some of the demands as protection of its interests and nationals in Ukraine and prevention of the country’s accession to the Western military alliance of NATO.

Also on Saturday, Ukraine’s Foreign Minister Dmytro Kuleba said the country was ready to negotiate to end the conflict, but would not surrender or accept any ultimatums.

"We will continue to fight. We are ready to negotiate but we are not going to accept any ultimatums and surrender," Kuleba said, adding that Russia was putting forward demands that were "unacceptable."

Commenting on the situation in the southern port city of Mariupol, the minister said it was besieged, but still under Ukrainian control.

He alleged that civilian lives would be saved if Ukraine had fighter jets and more attack planes to destroy large military columns.

"If we had more planes we would have been able to save many more civilian lives mainly because the main striking force of Russia is in the air and they indiscriminately choose to attack. As we continue to fight we will need more and more weapons," Kuleba added.

Russia has reportedly destroyed almost all of Ukraine’s warplanes.

Kiev has urged NATO and the US, on several occasions, to set up a no-fly zone over the country. Washington and the Western military alliance have roundly rejected the demand for fears of being dragged into a war with Russia.

In a related development, US President Joe Biden authorized an additional $200 million in weapons and other military assistance for Ukraine, the White House said.

The decision brings total US military aid provided to Ukraine to $1.2 billion since January 2021, and to $3.2 billion since 2014, when the conflict over Donetsk and Lugansk started.

In a memorandum to Secretary of State Antony Blinken, Biden directed that up to $200 million allocated through the Foreign Assistance Act be designated for Ukraine's military.

The funds can be used for weapons and other military articles from the US Defense Department's stock, as well as military education and training to help Ukraine against Russia.

Ukraine has been asking for more Javelin anti-tank weapons and Stinger missiles to shoot down Russian military aircraft.

"Around 1,300" Ukrainian troops have been killed since Russia started the military operation, the country's President Volodymyr Zelensky said on Saturday.

Zelensky made the disclosure at a media briefing, the first time Kiev had given such a toll since the beginning of fighting.

On March 2, Russia said it had lost nearly 500 soldiers, but has not updated the figure since.

The Ukrainian president claimed that Russia had lost "around 12,000 men."

Around 13,000 people were evacuated from a number of Ukrainian cities on Saturday, said Deputy Prime Minister Iryna Vereshchuk, almost twice the number who managed to get out the previous day.

Vereshchuk said in an online message that no one had managed to leave the besieged city of Mariupol and blamed obstruction by Russian forces, contradicting Moscow’s words that Ukrainian nationalists were intentionally trapping people there.