Russian President Dmitry Medvedev on Saturday landed in Lisbon for a summit with NATO leaders at which the two sides were expected to launch talks on linking proposed anti-missile systems, DPA reported.
NATO leaders late Friday agreed to set up an alliance-wide missile shield linking US long-range interceptor rockets with shorter-range European systems.
On Saturday they were expected to invite Russia to talks on linking its early-warning system into the network as a confidence- building measure.
Earlier on Saturday, German Chancellor Angela Merkel said that the summit would be "a milestone" in cooperation with Russia.
"A former military opponent is clearly becoming a partner: it's a change in cooperation which you could call historic," Merkel said.