F-16 fighter jets are being transferred from Denmark and the Netherlands o Ukraine, U.S. Secretary of State Antony Blinken has said, adding that these aircraft will be flying in the Ukrainian skies already this summer.

"I am also pleased to announce that as we speak the transfer of F-16 jets is underway, coming from Denmark, coming from the Netherlands. And those jets will be flying in the skies of Ukraine this summer to make sure that Ukraine can continue to effectively defend itself against the Russian aggression," he said at the NATO Public Forum in Washington on Wednesday.

The U.S. Secretary of State also noted the work that NATO Allies have done to put together more air defense systems for Ukraine, particularly Patriots, but also many other systems because "that's the key to so many things."

"It's the key to defending Ukraine's infrastructure. The key to defending its people. It's the key to defending its forces. It's also the key to making sure that we are unblocking the private sector and economic investment in Ukraine that will also be essential to Ukraine's successful movement forward," he said.

Blinken emphasized that people make investment in secure environments, so the announced air defense systems have been "job number one for Ukraine and as a result for the Alliance that is supporting it."