Russia on Wednesday issued a fresh ultimatum to Ukrainian fighters still trapped in the city of Mariupol to surrender, while Western governments pledged more military aid to Kiev.
Thousands of Russian soldiers, backed by artillery and rockets, are advancing in what Ukrainian officials describe as the Battle of Donbass.
After the previous ultimatum for surrender expired and as midnight approached yesterday, the Russian Defense Ministry said that no Ukrainian soldiers laid down their weapons and renewed the deadline, as Ukrainian leaders pledged not to surrender.
The Russian Defense Ministry said that "the Russian armed forces, based on purely humanitarian principles, propose once again that the fighters of the nationalist battalions and foreign mercenaries stop their military operations from 2:00 p.m. Moscow time on April 20 and lay down their arms."
A Russian official accused the Ukrainian authorities of being the reason for not leaving its soldiers because it tells them that it is impossible to evacuate them, and that it does not allow civilians to leave and uses them as human shields, according to his description.
The Russian official indicated that the remaining Ukrainian forces in "Azovstal" are ready to hand over their weapons, but with the permission of Kyiv.
On the other hand, a Ukrainian presidential adviser said late on Tuesday that Russia had bombed the Azovstal steel plant, the main remaining stronghold in Mariupol, with bunker-busting bombs.
"The world is watching on the Internet the killing of children and does nothing," Chancellor Mikhailo Podolak wrote on Twitter.
new western military aid
Meanwhile, the United States, Canada and Britain said they would send more artillery weapons to Ukraine.
"We will continue to provide them with more ammunition, and we will give them more military assistance," White House spokeswoman Jen Psaki said, adding that new sanctions were being prepared against Russia.
Multiple sources told Reuters that US President Joe Biden is expected to announce a new military aid package, the same size as last week's $800 million package, in the coming days.
In turn, the Pentagon said on Tuesday that Ukraine's partners had provided it with additional military aircraft and spare parts to repair others in Kyiv's arsenal that were damaged or not working.
Pentagon spokesman John Kirby did not provide details of which countries had provided planes, but acknowledged that new transfers had occurred, and said Ukraine had more operational combat aircraft than it did two weeks ago.
Last week, the Biden administration announced an additional $800 million in aid, including artillery systems, artillery shells, armored personnel carriers and autonomous coastal defense boats, to expand the range of equipment being sent to Kyiv to include new types of heavy equipment.
Appeals for evacuation
On the field level, a commander in the Ukrainian Marine Corps, which is defending the last stronghold of the Ukrainian forces in the besieged city of Mariupol, said, "We may face our days, if not our last hours."
"The enemy is outnumbering us ten to one," said Sergei Volina of the 36th Separate Marine Brigade, which is holed up in the huge Azovstal factory besieged by Russian forces.
"We appeal and plead with all world leaders for our help," he added in a video clip, adding, "We ask them to use the procedure of removing the troops and transferring us to a third-party area."
A new military stage
On Tuesday, Russian Foreign Minister Sergei Lavrov confirmed the start of the next stage of the Russian military operation in Ukraine, and said that this stage would be very important.
Russian Defense Minister Sergei Shoigu also stressed that Russian military operations are going according to plan.
During a meeting held in the Russian Defense Ministry, he accused the United States and Western countries of trying to prolong the Russian military operation in Ukraine by increasing their arms supplies to the regime in Kyiv.
Yesterday, the Russian Defense Ministry announced the targeting of 31 Ukrainian military installations.
Its spokesman, Igor Konashenkov, said that Russian forces had killed about 180 Ukrainian soldiers during "high-precision" missile strikes, which targeted sites where Ukrainian forces and military vehicles were stationed.
For his part, UN Secretary-General Antonio Guterres called for a humanitarian pause for four days at the end of next week, when Orthodox Christians celebrate Easter, to allow civilians to escape and for UN agencies to deliver humanitarian aid.