Sources: Vasiliy Lomachenko's team seeks OK to train for proposed George Kambosos fight outside Ukraine

As Vasiliy Lomachenko works to help defend Ukraine from Russia's ongoing invasion, efforts are being made by his team to allow him to leave his native country to train for a proposed fight against undisputed lightweight champion George Kambosos, sources told ESPN on Tuesday.

Lomachenko, 34, joined a territorial defense battalion earlier this month and has been working on a security detail at the Ukraine-Russia border, sources told ESPN. Under martial law in Ukraine, able-bodied men between the ages of 18 and 60 are prohibited from leaving the country to aid in defense against Russia.

Lomachenko, a former three-division champion and two-time Olympic gold medalist, agreed to a deal in February to fight Kambosos on June 5 in Melbourne, Australia. Lomachenko was in Greece but returned to Ukraine shortly after the Russian invasion began.

Kambosos (20-0, 10 KOs) hasn't agreed to a deal yet, according to sources, but he is closing in on a pact with promoter Lou DiBella for a title defense at Marvel Stadium, whether it's against Lomachenko or Devin Haney, the rising star who remains in the mix for the assignment.

Officials involved with the bout require that a Kambosos opponent be locked in by the end of March to allow for the typical eight-week promotional push, sources said. If there's no clarity regarding Lomachenko's ability to leave Ukraine and set up training camp by next week, talks will intensify with Haney, who is promoted by Eddie Hearn, according to sources.

However, Lomachenko (16-2, 11 KOs) remains Kambosos' focus. If the fight happens, it will take place on a Sunday afternoon in Australia to accommodate a prime-time ESPN telecast stateside on Saturday.

Lomachenko, ESPN's No. 7 pound-for-pound boxer, has recorded two consecutive wins since he lost his unified lightweight championship to Teofimo Lopez in October 2020. After undergoing surgery to repair a torn rotator cuff, an injury he dealt with during the Lopez fight, Lomachenko scored a ninth-round TKO of Masayoshi Nakatani in June. In December, he floored Richard Commey en route to a wide-points victory.

Kambosos, a native of Sydney, Australia, scored an upset split decision over Lopez in November, a fight that was named ESPN's Upset of the Year. Lopez was a 10-1 favorite and regarded as one of the best pound-for-pound boxers in the world. Both boxers were knocked down in one of the best action bouts of 2021.

The career-best performance catapulted Kambosos, 28, to superstardom in Australia and placed him in the driver's seat of boxing's hottest division. Kambosos insisted in the immediate aftermath that he would forgo a routine title defense to chase the toughest challenge at lightweight, and that's exactly what Lomachenko presents. But Haney, too, would represent a formidable test.

The 23-year-old from Las Vegas broke out in 2021 with victories over Jorge Linares and Joseph Diaz Jr. Haney is rated No. 4 by ESPN at lightweight; Kambosos is No. 1.

Lomachenko, who is rated No. 2, remains the front-runner for the bout if the situation in Ukraine allows him to compete. His longtime close friend, unified heavyweight champion Oleksandr Usyk, also joined a territorial defense battalion in Ukraine. Usyk owes Anthony Joshua a rematch that was slated for May or June, but Hearn told ESPN earlier this month that Joshua could take an interim bout while Ukraine is at war.

"It's a very unique, personal, emotional situation and I don't think we can really fathom what's going on there and what's going through the minds of people involved there," Hearn said.