The United States and Ukraine on Monday began joint military exercises in western Ukraine, dpa reported.
The Rapid Trident 2014 drill kicked off early Monday, according to a dpa reporter at the Yavoriv military base in western Ukraine, close to the border with Poland.
The exercise, which is set to last until September 26, involves some 1,300 troops from 12 NATO members including Germany, Britain, Poland, Lithuania and Canada, as well as non-NATO members Azerbaijan, Georgia and Moldova, the US Army said.
The exercise is being held at the request of the Ukrainian government and military, it said.
The Yavoriv military base lies some 1,200 kilometres west of Ukraine's eastern Donetsk and Luhansk regions, where over the past months some 3,000 people have been killed in fighting between government troops and pro-Russian separatists.
A fragile ceasefire was declared 10 days ago. There were no reports of shooting on Monday.