to help put an end to the fighting

US welcomes Ukraine-Russia prisoner swap but says more can be done

Ukrainian President Petro Poroshenko welcomes Ukrainian servicemen after their release

The United States on Thursday welcomed the mass prisoner swap by Ukraine and Russian-backed separatist rebels, but called on both sides in the conflict to go farther, asking Moscow to help put an end to the fighting.

On Wednesday, authorities in Kiev and the rebels who control large parts of eastern Ukraine exchanged more than 300 prisoners, in one of the largest such exchanges since the outbreak of the insurgency almost four years ago.

"This exchange is one step toward implementation of the Minsk agreements" signed in February 2015, the US State Department said in a statement.

The peace deal, brokered by Germany and France, led to a reduction in fighting but is still violated almost daily.

The US called on both sides to "fully implement their Minsk commitments including through a true 'all-for-all' detainee exchange; a full ceasefire; the withdrawal of heavy weapons; safe and secure access for OSCE Special Monitoring Mission monitors; and humanitarian access to the conflict zone."

"Russia, which started this conflict and perpetuates it through active leadership of military units on the ground that attack Ukrainian positions daily, must commit to bring it to an end," the State Department said.

The war in the former Soviet republic broke out in April 2014, after Russia annexed Crimea the previous month. It has already claimed more than 10,000 lives.

Ukraine and its Western allies accuse Russia of funneling troops and arms across the border.

Moscow has denied the claims despite overwhelming evidence that it has been involved in the fighting and its explicit political support for the rebels.

The United States reiterated its call for a peacekeeping force with a "broad mandate for safety and security across the entire conflict zone" that would also include "control of the international border, and responsibility for ensuring the cantonment of heavy weapons."

The West and Moscow are currently in talks about the eventual deployment of such a force and the extent of its mandate, with Russia favoring a more restrained role.