There have been monumental efforts, especially by Poland, to get weapons into Ukraine and to the front lines.

But a senior official told ABC News there are indications Russia may attack one of those supply chains in Poland before it gets to Ukraine, potentially using air power.

Russian forces have created heavily fortified areas from which to launch long-range artillery, the official said, meaning they can shell cities from a distance rather than send troops into them. Ukrainian President Volodymyr Zelenskyy has repeatedly requested air power assistance in order to destroy these fortified areas.

Ukrainians have seen success in attacking Russian resupply areas, mostly in the north but also among smaller, moving groups.

-ABC News' Martha Raddatz

Ukrainian President Volodymyr Zelenskyy has filmed himself from the street just outside his office, but for the first time since the invasion began, he posted a video message from inside.

“We’re not scared, because you’re not scared,” he told Ukrainians who have taken up arms and told Russia it is not welcome.

“So, I stay here at Bankova Street,” Zelenskyy said. “I’m not hiding from anyone and not afraid of anyone as long as it takes to win in this war, our truly patriotic war.”

The latest address was filmed as a selfie in which he showed a view of Kyiv on Monday night.

“This is Kyiv at night outside the window. This is our office. Monday night. You know, we’re used to saying Monday is a hard day,” he said. “But the country is at war now, so every day is Monday.”

-ABC News’ Christine Theodorou

Ukraine’s national nuclear regulator told the International Atomic Energy Agency on Monday that a new nuclear research facility producing radioisotopes for medical and industrial applications had been damaged by shelling in the city of Kharkiv on Sunday.

The incident did not cause any increase in radiation levels at the site.

The nuclear material in the facility is always subcritical, the IAEA said, and the inventory of radioactive material is very low, so the damage reported would not have any radiological consequence.

Eight of Ukraine’s 15 reactors are currently operating, the IAEA said, citing Ukraine’s nuclear regulator.

IAEA Director General Grossi noted there have been several episodes compromising safety at Ukraine’s nuclear sites, including a recent fire at the Zaporizhzhya Nuclear Power Plant, where two reactors are still operational.

-ABC News’ Christine Theodorou

Ukraine and Russia’s foreign ministers have agreed to meet on the sidelines of a diplomatic forum in Turkey on Thursday in what will be the highest level direct meeting between the two sides since Russia’s invasion.

The meeting was agreed following a call between Turkish President Recep Tayyip Erdogan and Russian President Vladimir Putin on Sunday.

Russia’s foreign ministry spokesperson Maria Zakharova earlier confirmed the two had agreed to a meeting. Ukraine’s foreign minister Dmytro Kuleba has also confirmed it.

It’s not clear that there is much the two will be able to agree on, but it still signals a readiness by Russia to talk. For now, Russia is continuing to put forward hardline demands that Ukraine guarantee it will never join NATO or the European Union.

-ABC News’ Patrick Reevell

The tower that provides the main signal to TV and radio in Kyiv has been struck by a Russian missile, leaving at least five dead, Ukrainian officials said.

Ukraine's Foreign Minister Dmytro Kuleba tweeted that the tower "is situated on the territory of Babyn Yar. On September 29-30, 1941, Nazis killed over 33 thousand Jews here. 80 years later, Russian Nazis strike this same land to exterminate Ukrainians. Evil and barbaric."

Ukraine's President President Volodymr Zelenskyy tweeted, "What is the point of saying «never again» for 80 years, if the world stays silent when a bomb drops on the same site of Babyn Yar? At least 5 killed. History repeating."

-ABC News' Christine Theodorou