President Jacques Chirac of France has visited Moscow for talks with his Russian counterpart Vladimir Putin.
Mr Putin took Mr Chirac around a secret space centre
The visit began with a tour of the secret Titov centre near Moscow, which collects spy satellite data, in what is seen as a sign of trust.
Mr Putin's talks with Mr Chirac come a day after a visit by German Chancellor Gerhard Schroeder.
Both trips are seen as an attempt to soothe Moscow's concerns over the expansion of Nato and the EU.
President Chirac was the first foreigner to visit the Titov centre, about 40kms (25 miles) west of Moscow.
The BBC's Steve Rosenberg in Moscow says the symbolism was not lost on President Chirac - who said he welcomed this "sign of trust".
During the tour on Saturday Mr Putin showed him models of two Russian satellites.
The older one was the size of a man and weighed 600kg (1300 pounds) - the modern type the size of a football and weighed two kg (four pounds).
"This is the difference 10 years makes," Mr Putin said.
Mr Chirac left Moscow at the end of the day.
Our correspondent says that in recent weeks relations between Russia and the west have been clouded by mistrust.
Europe has expressed concern about the state of Russian democracy.
Russia remains anxious it is losing key political and economic levers, as eight countries from its own former sphere of influence join the European fold.
Mr Putin was also looking for reassurance from his French and German allies over Nato.
The enlargement of the military alliance to seven Central and Eastern European countries on Friday had long been announced - but it was nevertheless not welcomed by Moscow.