Nearly 40,000 civilians were evacuated from Ukraine Thursday, though routes out of Mariupol and Volnovakha remain completely blocked, according to Ukrainian President Volodymyr Zelenskyy.

During his latest address from his office in Kyiv, Zelenskyy accused Russia of deliberately striking an area in the besieged eastern city of Mariupol where people were due to gather for evacuation Thursday.

“They have a clear order to hold Mariupol hostage, to torture it, to carry out constant bombardment," Zelenskyy said.

"This is outright terror. Blatant terror," he said. "We are all dealing with a terrorist state."

The president also expressed concern that Russia’s intense propaganda about biological and chemical weapons means it may be preparing to use them in Ukraine -- a sentiment recently voiced by the U.S. State Department.

"They accuse us. ... Again us! That we are allegedly developing biological weapons. Allegedly, we are preparing a chemical attack," Zelenskyy said. "This makes me really worried, because we’ve been repeatedly convinced: If you want to know Russia's plans, look at what Russia accuses others of."

He added that the public support for Ukraine in European countries has convinced him Ukraine will succeed in joining the European Union.

"Today, when I see the support of the people of each country in the squares of European capitals, I know that the Ukrainian people are already in the European Union," Zelenskyy said.

-ABC News' Patrick Reevell

Joey and Paula Reed, the parents of ex-Marine Trevor Reed who has been held in a Russian prison for over two years, said they are more fearful for their son's life after he called them from Russia.

The couple said in statement that Reed is "seriously ill" and was "coughing up blood multiple times a day, [and] running a fever."

"He also reports a broken rib because 'something fell' on him,' and to make matters worse, he's being underfed," the Reeds said.

During the call, Trevor Reed was sent to the "prison disciplinary ‘commission,'" according to his parents, who added they feared he was being sent to solitary confinement.

The couple recently spoke with President Joe Biden about their son's imprisonment.

"We were able to tell him [we] spoke to President Biden and anxiously await hearing from the White House as the President promised. Trevor increasingly feels left behind, and it’s heartbreaking for us to hear that from our son, whose service we are so proud of," they said.

-ABC News' Conor Finnegan

Russian troops have advanced about 3 miles toward Kyiv in the past day, bringing them within roughly 9 miles of the city center, according to a senior U.S. defense official.

The troops are to the northwest of Kyiv, in the area of the Hostomel Airport, which is about 5 miles from the outer city limits.

Two lines of advance from the northeast are also making progress on their push to Kyiv. The closest of these troops is now approximately 25 miles from the heart of the city, the official told reporters during a Thursday evening briefing.

Some troops from one of those lines of advance, emanating from above the town of Sumy, seem to have turned around, heading back northeast, though the reason for the about-face is unclear, the official said.

Kyiv remains "well-defended" by Ukrainian forces, the official said. Security assistance continues to flow into Ukraine, including air-defense systems, according to the official.

Since the start of the invasion, Russian forces have fired more than 775 missiles against Ukraine, the official said.

-ABC News' Matt Seyler

Gen. Mark A. Milley, the chairman of the Joint Chiefs of Staff, spoke with his military counterparts in France, Poland, Romania and Bulgaria Thursday about the latest developments in Ukraine, according to the Pentagon.

While the Pentagon didn't provide many details about his discussions with the military leaders, it said they shared assessments and intelligence.

Milley also discussed the recent deployment of U.S. military forces to Poland and Romania with their respective military leaders, according to the Pentagon.

-ABC News' Luis Martinez