Ukraine’s highest profile combat unit is seeking English-speaking recruits at a time when the impending presidency of Donald Trump means that Kyiv is expected to come under intense pressure on the battlefield.

Azov, a volunteer brigade whose decade-old nationalist origins have made it a target of Russian propaganda, plans to form an international battalion to boost its numbers as Ukraine heads into a fourth year of full-scale war.

The unit commander, whose call sign is Karl, said Azov largely hoped to recruit people with military experience “because Ukraine is smaller than Russia” and needs all the help it can get in a struggle of international significance.

“We are fighting to not let Russia become closer to Europe,” he said, arguing that if Ukraine were to fall, Moscow would go on to threaten Poland, the Baltic states and other nations, some of whom were smaller than Ukraine.

Fifteen Britons, acting as soldiers or volunteer workers, have been killed since the start of Russia’s full-scale invasion, including two whose deaths have been announced this month: the frontline medic Jordan Maclachlan, 26, from Scotland and the former British Army soldier Jake Waddington, 34, a member of the International Legion.

They are among a steady flow of Britons and other westerners who have joined Ukraine’s armed forces in a near three-year conflict that, as of early December, had claimed the lives of 43,000 Ukrainian soldiers and, according to intelligence estimates, roughly three times as many Russians.

Travelling to Ukraine to fight in its armed forces is not illegal, unless you are a member of the UK armed forces, though it is not encouraged. In the early stages of the war, the then defence secretary Ben Wallace said Britons without military training would be of little use to Ukraine’s military.

Non-Ukrainians seeking to join Azov have to complete a recruitment process, including interviews in Kyiv, which Karl said includes a psychological assessment “and a polygraph test, to check they do not work undercover for Russian special forces”.

Initial training will last two to three months, even for those with military experience, in groups of about 80 to reflect the realities of the Ukrainian battlefield, where there is a heavy use of drones and artillery. “The training of some soldiers in Europe hasn’t changed much since the second world war,” Karl said.

After training, those willing to stay on are expected to join infantry assault units. Karl acknowledged that recruits would eventually be placed in dangerous situations. “The reality can be rather bad, it’s a war,” the commander said.

Azov is now operating near Toretsk in the east of Ukraine, a ruined town split between both sides’ armies. The situation across the entire front is expected to worsen for Ukraine because Trump is expected to curtail or cut the flow of US military aid while trying to end the conflict.

Questions have been raised in the past about the effectiveness of the International Legion, the dedicated unit for foreign fighters at the start of the war, with accusations of corruption and poor leadership leading to heavy casualties.

However, Azov is one of the most popular units for Ukrainians to join, even as the willingness of civilians to join the military has dropped. It is considered to be better run than other brigades and is seen as a tenacious defender of Ukraine, having fought in a last stand in Mariupol in 2022.

The brigade began life as a volunteer militia fighting Russian-backed separatists in 2014, and some of its leaders held ultra-nationalistic and far right views. Russia designated it a terror group in 2022, and for several years the US refused to supply it arms directly.

However, Azov has changed over a continuous decade of fighting. In the summer, a US review led to the end of the weapons ban, concluding the unit had not committed any human rights violations. At the time, Russia accused Washington of being willing to “flirt with neo-Nazis”, comments Azov members dismiss as propaganda.

“Our deeds in Mariupol changed a lot,” Karl said. In May 2022, the brigade was surrounded at the Azovstal plant, and nearly 2,500 put down their arms after running out of ammunition. An estimated 900 are still held prisoner in Russia.