The Ukrainian military has completed its combat operation in Mariupol and has ordered the last troops stationed at a surrounded steel mill to evacuate.John Moore/Getty Images

The Ukrainian military has completed its combat operation in Mariupol and has ordered the remaining troops stationed at a surrounded steel mill to evacuate.

According to Ukrainian officials, the brigade that steadfastly defended a steel plant as Ukraine's final bastion in the port city concluded its operation Monday after more than 260 troops were evacuated and transferred to Russian-controlled territory.

Ukrainian President Volodymyr Zelensky said the evacuation was conducted to save the lives of the defenders who fought the Russian invaders at the Azovstal steel facility for weeks, per Time. He said they were brought to areas under separatist control and those that sustained serious injuries were being treated, while an unknown number of fighters remained in the facility waiting for succeeding rescue efforts.

"Ukraine needs Ukrainian heroes to be alive. It's our principle," Zelensky said.

Russian forces continued their attack on eastern Ukraine on Tuesday, with full control of the besieged port city of Mariupol underway. Eastern Ukraine is now the center of a grueling battle that exhibits the markings of a brutal endurance war, as per a Los Angeles Times report.

Ukrainian Troops Evacuated to Russian-Controlled Areas

Overnight, 264 Ukrainian defenders were evacuated from Azovstal under Russian military escort, including more than 50 who were severely wounded. More than 200 others were taken to Olenivka, a town controlled by pro-Russian separatists, via a humanitarian corridor.

The evacuation agreement appears to have been negotiated secretly under the supervision of the International Red Cross and the United Nations. It was first disclosed Monday by the Russian Defense Ministry, but it is still unclear.

Iryna Vereshchuk, Ukraine's Deputy Prime Minister, announced on Tuesday that the critically wounded servicemen would be swapped for Russian prisoners of war when their health "stabilizes."

Despite the takeover of Mariupol in Ukraine's southeast, Moscow's eastern campaign appears to have halted. Russian forces make costly but steady advances even as Ukrainian forces launch counteroffensives to slow Moscow's progress near the Seversky Donets river.

The assertion could not be independently confirmed, but if true, it allows Ukrainian soldiers to pressure Russian supply lines to Izium, 70 miles southeast of Kharkiv.

Russia-Ukraine Peace Talks Stalls

Meanwhile, peace talks between Russia and Ukraine have come to a halt, according to The Guardian.

According to Russian deputy foreign minister Andrei Rudenko, virtually no peace talks are currently taking place, accusing Ukraine of withdrawing from the talks.

"No, the negotiations are not continuing," Rudenko told reporters in Nizhny Novgorod, according to the Russian Interfax news agency. He claimed that Ukraine has essentially abandoned the bargaining table.

On the other hand, Ukraine's top presidential adviser and negotiator, Mykhailo Podolyak, blame Russia's "stereotypical mindset" for the stalling of the peace talks.

There have been "no significant changes, no progress" since the two delegations met in Istanbul in late March, he said.

There are various reasons for the halted peace talks, according to Podolyak: "Russia does not demonstrate the key," which is the present international dynamics and Russia's "extremely negative role."

He added that Russia does not comprehend that the war is "no longer going on according to the rules, their plans, and schedule," and that "the resistance of Ukraine, the professional resistance just grows," which is why Russia can never achieve its objectives.