Russian Presidential Aide Vladislav Surkov and U.S. Assistant Secretary of State Victoria Nuland focused on issues concerning security in Donbas at their talks in Moscow, the U.S. Embassy to Russia said on Friday.

The negotiators concentrated on the issue of maintaining security within the Minsk agreements, including ways to secure a complete ceasefire, the withdrawal of heavy artillery and to ensure Organization for Security and Cooperation in Europe (OSCE) representatives' unhindered access to the eastern part of Ukraine as soon as possible, the American diplomatic mission said in a report seen by Interfax.

The discussions were very detailed, thorough and constructive, it said.

During the meeting, the sides discussed further steps to implement the Minsk agreements, in order to support 'Normandy Four' efforts as part of the Ukrainian settlement process, the embassy said.

They once again discussed the current work to fulfill the political and humanitarian aspects of the Minsk agreements in support of the 'Normandy' process, it said.