Patriot missiles are among the most important weapons Ukraine has to intercept Russian airstrikes. (AFP pic)WASHINGTON: The Trump administration on Friday green-lit the sale of 500 Patriot missiles to Ukraine, the state department said, but the Ukrainian president warned deliveries could take years.

The approval, which goes to Congress for review, comes after weeks of complaints by Ukrainian authorities that its supplies of the interceptor missiles were dwindling.

"The proposed sale will improve Ukraine's capability to meet current and future threats by improving its integrated air and missile defence capabilities," the department said in a statement.

The statement did not provide an estimate for when the weapons could be delivered to Ukraine.