Russian Defense Ministry reported that an estimated 6,824 foreign mercenaries from 63 countries have arrived in Ukraine to fight for Volodymyr Zelensky's government. 

One thousand mercenaries have been eliminated, while thousands more are still deployed in Ukraine, according to the ministry.

The ministry added that four hundred foreign mercenaries have taken refuge in Mariupol, where nationalist forces, including neo-Nazis, have refused to surrender.

The largest group of foreign fighters (1,717) came from Poland, while around 1,500 came from the United States, Canada, and Romania. Up to 300 people arrived from the United Kingdom and Georgia, respectively, while 193 arrived from Turkish-controlled areas of Syria.

Major General Igor Konashenkov, the spokesperson for the Defense Ministry, announced these figures on Sunday. According to the general, Russian forces killed 1,035 foreign mercenaries, and 912 fled Ukraine, leaving 4,877 active in Kiev, Kharkov, Odessa, Nikolaev, and Mariupol.

Approximately 400 of these foreign fighters remain with Ukrainian nationalist battalions in the besieged port city of Mariupol. 

With the majority of the city under Russian control, these forces have been deployed at the massive Azovstal metallurgical plant, an 11-square-kilometer Soviet-built factory complex.

“Most of them are citizens of European countries, as well as Canada,” Konashenkov stated.

The top military figure added that the Russian forces have intercepted radio communications from the plant in six foreign languages.

After the surrender of more than 1,000 members of Ukraine’s 36th Marines Brigade at the Ilyich Steel and Iron Works in Mariupol earlier this week, which Ukraine denies, the Russian military offered the defenders at Azovstal a final chance to lay down their arms and surrender on Sunday morning, promising that “all who lay down their weapons are guaranteed the preservation of life.”

No such surrender occurred, and heavy gunfire could be heard near the plant on Sunday afternoon. "If there is any more resistance, they will all be destroyed," Konashenkov said.

“Let me remind you that foreign mercenaries do not have the status of ‘combatants’ under International Humanitarian Law,” Konashenkov said. “They came to Ukraine to earn money by killing Slavs. Therefore, the best that awaits them is a criminal liability and long prison terms.”

Within days of the start of the war in Ukraine, Kiev government promised visa-free entry to foreigners willing to fight Russian forces. 

Potential recruits went to Ukrainian embassies across the West, signed up to fight – often with the blessing of their own governments – and made their way to the front lines.

According to a spokesperson for Ukraine's so-called "International Legion," sending untrained volunteers to the front lines is becoming more of a hindrance than a help, and supplies of firearms and ammunition are running low.

Some of those who traveled shared horror stories online about being sent to the front lines with insufficient weapons and ammunition, while recruitment suffered after a Russian missile strike destroyed a training center for these foreigners near the Western Ukrainian city of Lvov. 

"At the time, up to 180 foreign mercenaries and a large number of foreign weapons were destroyed," Konashenkov said.