Ukraine will now seek fourth-generation fighter jets, such as the US F-16, after securing battle tanks, says Yuri Sak, adviser to the Ukrainian Minister of Defense Oleksy Reznikov.

Ukraine got a big boost to its forces yesterday when Germany and the US announced they would send tanks to Kyiv, ending weeks of diplomatic deadlock over the issue.

"The next big thing now will be fighter jets," Sack said.

Ukraine's air force has a fleet of aging Soviet-era fighter jets that were produced before Kyiv declared independence more than 31 years ago.

Military aircraft are used to intercept and attack Russian positions.

"If we get (Western fighter jets), the advantages on the battlefield will be huge... It's not just about the F-16 (US multi-role fighter jets): fourth-generation jets, that's what we want," Sack said.