The Netherlands and Denmark on Sunday announced that they will send dozens of F-16 fighter jets to Ukraine, a move that Kyiv hopes will bolster up its air defences amid Russia’s full-scale invasion.

The announcements were made as Volodymyr Zelenskyy, Ukraine’s president, made surprise visits to both countries over the weekend.

Meeting the Dutch prime minister, Mark Rutte, Mr Zelenskyy spoke of a "breakthrough agreement" regarding the transfer of F-16s.

"Starting today, we have details. They [F-16s] will be in the Ukrainian sky. Thank you, Netherlands! Thank you, Mark! Thank you to everyone who helps! We will win!" he posted on Telegram, later adding the Netherlands will transfer 42 aircraft.

Mr Rutte himself confirmed the agreement, telling a press conference on Sunday Ukraine will receive F-16s from the Netherlands and Denmark after the pilot training is over.

He confirmed the Netherlands currently has 42 F-16 fighters, but there may be more aircraft provided.

"I can't say for sure, but we are working from the point that we have 42 here in our country," the Dutch prime minister said.

Later, Danish prime minister Mette Frederiksen added the country will donate another 19 F-16 fighter jets to Ukraine, hoping to deliver the first six by the end of the year and another eight next year.

In May, US president Joe Biden officially confirmed that the US military would start training Ukrainian pilots for the F-16, which already started last week.

Ukraine, which has long been pushing for modern fighter jets, has indicated it needs four squadrons, that is 48 F-16s, to effectively deter Russian aggression.