Russian diplomats are meeting this week with officials from the United States and its NATO allies for security negotiations in three European cities, writes apnews.com.

Russian and U.S. negotiators launched the talks in Geneva on Monday. They will be followed by Russia-NATO talks in Brussels and a meeting in Vienna of the Organization for Security and Cooperation in Europe over the course of the week.

The Kremlin demanded that Washington and its allies make a binding pledge excluding NATO’s expansion to Ukraine, Georgia or any other ex-Soviet nations.

Moscow has also demanded that the U.S. and its allies make a commitment not to deploy weapons or conduct any military activities in Ukraine and other ex-Soviet nations.

The U.S. and its allies have roundly rejected the demand for NATO not to admit Ukraine or any other new members, emphasizing that a key alliance principle is that membership is open to any qualifying country and no outsiders have veto power.

The Western allies insist that NATO’s doors must remain open to them. In 2008, NATO promised to eventually embrace the two nations, although it hasn’t offered them a specific road map to membership.