The U.S. will soon deliver four more advanced missile systems to Ukraine. U.S. officials say the highly mobile artillery missile systems, known as HIMARS, will be part of a new $625 million aid package, AP reports.

In recent weeks, the U.S. has also provided funding under a separate program - the Ukraine Security Assistance Initiative - so that another 18 HIMARS will be purchased under longer-term contracts.

The latest aid package is also expected to include other munitions and equipment.