Ukrainian Minister of Foreign Affairs Dmytro Kuleba on Monday called for NATO to enforce a no-fly zone over Ukraine, saying Russian planes were targeting civilians.

"The Russian Air Force dominates in the skies and continues bombing our cities and killing many civilians," Kuleba told George Stephanopoulos on "Good Morning America."

U.S. and NATO officials have rejected calls from Ukrainian officials to impose a no-fly zone, saying doing so could provoke Russia, perhaps pulling other European countries and NATO members into the conflict. The U.S. and NATO have offered other military aid, including a possible deal to send aircraft to Ukraine.

"We believe that the rejection of the idea of the no-fly zone is based in the lack of confidence in the strength of NATO as an alliance," Kuleba said. "Because the military might of NATO is incomparably bigger compared to Russia. So why would Russia dare to shoot down a NATO plane, knowing it is doomed, eventually doomed, if a war with NATO begins."

Kuleba over the weekend had urged the international community to help in the struggle against “Russian barbarians.” He posted a photo on Twitter on Sunday of an unexploded bomb, which he said landed on a residential building in Chernihiv.

Ukrainian officials said Russia’s proposal on Monday to open "humanitarian corridors" for cities in Ukraine is not a genuine offer because it offers to evacuate civilians only to Belarus and Russia.

Iryna Vereshchuk, a Ukrainian vice prime minister, in a televised briefing called that "unacceptable" and said Ukraine had demanded instead that civilians be allowed to evacuate to other parts of Ukraine.

Russia’s Defense Ministry had said it would open a corridor from towns and villages north of Kyiv, where heavy fighting is taking place, but that would allow people to travel to the Belarusian city of Gomel and then be flown to Russia. Russia also offered corridors near the besieged northeastern and eastern cities of Kharkiv, Sumy and Mariupol, but that would also only allow people to leave over the border to Russia.

"This is an unacceptable option of humanitarian corridors. Our people from outskirts of Kyiv won’t go to Belarus and then to Russia," Vereshchuk said.

She said that Ukraine wants civilians north of Kyiv to be permitted to leave to the capital and for those from Kharkiv to be allowed to western cities by train, and from Mariupol north to the central city of Zaporizhzhia.

"We delivered our proposal on how the corridors should be organized," Vereshchuk said, later adding, "Humanitarian aid is prepared for a number of towns in the east and south. We ask Russia to confirm these corridors and provide ceasefire."

Russia has repeatedly violated its own ceasefire since offering humanitarian corridors for Mariupol and another eastern town Volnovakha, including shelling evacuation points in Mariupol according to officials there. The Red Cross, which is trying to organize the evacuations, has said the agreements currently are too vague and without clear understandings for routes out.

Russia said Monday's offer for the corridors was made following a lengthy phone conversation between French President Emmanuel Macron and Russian President Vladimir Putin on Sunday.

Vereshchuk said Russia was trying to exploit Macron’s name for a disingenuous offer of corridors.

"I hope president Macron understands that his name and good intentions are manipulated by Russia," she said.

-ABC News’ Patrick Reevell

More than 1 million people fleeing Ukraine have arrived in Poland since the Russian invasion began on Feb. 24, the Polish Border Guard said on Monday.

A record 142,000 people arrived on Sunday, the guard said on Twitter. On Monday, about 42,000 people had crossed the border before 7 a.m. local time.

As of Sunday, more than 1.5 million people had fled the war in Ukraine, marking the "fastest growing refugee crises in Europe since World War II," according to Filippo Grandi, the U.N. high commissioner for refugees.

Russian forces have attacked Ukrainian communications infrastructure to "reduce Ukrainian citizens' access to reliable news and information," the U.K. Ministry of Defence said on Monday.

"Russia reportedly struck a TV tower in Kharkiv yesterday, suspending broadcasting output," the Ministry’s update said.

Russian forces on March 1 struck a TV tower in Kyiv, the capital.