The Kenyan government estimates that around 200 of its nationals have been recruited to fight for Russia. The exact number remains unclear, as Nairobi maintains that none of them travelled through official channels.

"Kenya and Russia have had long relations since independence, literally. So this, in my view, becomes a very unfortunate episode of otherwise very positive and cordial relations between our two countries," he added.

Mudavadi has told the BBC that Kenya's engagement with Russia will focus on curbing illegal recruitment practices, including discussions on visa policy and bilateral labour agreements excluding military conscription.

He said the Kenyan authorities had closed more than 600 recruitment agencies suspected of duping Kenyans with promises of jobs overseas.

So far 27 Kenyans who had been fighting in Russia have been repatriated, he said, with authorities providing psychological care to address their trauma and "de-radicalise" them.

It is not clear how many Kenyans have died fighting for Russian forces, and Russia has not formally addressed such reports. Relatives who have approached the Russian embassy in Nairobi for answers report being turned away.

"Families that we've spoken to say they have not been able to bury their loved ones because their bodies are still on the other end," Kenya's foreign minister said.

"It is difficult because, remember, it depends on where the body has been found. There some have been found in Ukraine - we are also working with the government of Ukraine to try and get the remains of those people repatriated."

Pressure has been mounting on the Kenyan government to act after the recent discovery of more bodies of citizens who had been recruited to fight for Russian armed forces.

Some of the affected families have told the BBC that they lay the blame squarely on Kenya's government, for failing to regulate and criminalise clandestine recruitment agencies.

But the Kenyan foreign minister rejects this.

"You cannot blame the government on this," Mudavadi told the BBC. "Where there are illegal recruitment agencies, we have scrapped them and we continue to scrap them."

Ukrainian intelligence assessment estimates that more than 1,400 people from 36 countries in Africa have been recruited to fight for Russia. Ukraine has also previously come in for criticism for trying to recruit foreign nationals, including Africans, to fight on its side.

Ukrainian officials have repeatedly warned that anyone fighting for Russia will be treated as an enemy combatant, and that the only safe route out is to surrender and be treated as a prisoner of war.

On Tuesday, the South African government said Russian President Vladimir Putin had pledged to help return South African nationals who had travelled to Ukraine to join Russian troops.

This was discussed during a phone call between Putin and South Africa's President Cyril Ramaphosa, officials say, with both leaders agreeing their governments will continue working together to finalise the process.

At least 17 South African men are reported to be on the front lines of the conflict.

Additional reporting by Nobuhle Simelane and Basillioh Rukanga