NATO leaders have rejected a proposal from Russian President Dmitry Medvedev to unite the country's missile defenses with a shield being built by the West, The Wall Street Journal reported Friday.

After a North Atlantic Treaty Organization summit in Portugal last week, Medvedev pledged to work with the transatlantic alliance on a missile defense system for Europe but insisted Moscow must be an "absolutely equal" partner.

Yet summit attendees told the Journal that US President Brack Obama and other leaders of the 28 allied nations diplomatically rebuffed Medvedev's plans, saying their own technical experts should examine the issue.

The experts will search for ways the two systems can cooperate and report back to a meeting of NATO and Russian defense ministers in Brussels in June, it added.

Medvedev's proposal goes way beyond the alliance's vision for cooperation and information between two systems rather than a single one, the newspaper said, citing NATO diplomats.

Moscow and NATO broke off all contacts two years ago following Russia's invasion of its tiny NATO-aspiring neighbour Georgia.

Last weekend's summit in Lisbon aimed to restore those relations, with the two sides finding particular agreement over Afghanistan.