US Secretary of State Condoleezza Rice has signed a missile defence deal with Poland. The agreement for Poland to host ten US interceptor missiles at a base 115 miles from Russia's western border has placed added strain on Moscow's ties with the West following its invasion of Georgia. Dr Rice and Polish foreign minister Radek Sikorski signed the deal in the presence of both the Polish president and prime minister. President Lech Kaczynski said the agreement marked "an important day in our history." The deal "strengthens Poland's position in the world," he said in a televised address on Tuesday. Poland and the US spent a year and a half negotiating, and talks had snagged on Polish demands that the US bolster its defences with Patriot missiles in exchange for hosting the new base. Washington gave in last week as Poland invoked the Georgia conflict to strengthen its case. The Patriots are meant to protect Poland from short-range missiles from neighbors such as Russia. Mr Kaczynsk said that the missile defence shield was purely a defensive system and not a threat to any nation, saying: "No one who has good intentions toward us and toward the Western world should be afraid of it." A day after Warsaw and Washington reached agreement on the deal, Russian general Anatoly Nogovitsyn warned Poland it was exposing itself to a missile strike by joining the American missile shield. But Nato Secretary General Jaap de Hoop Scheffer used unusually strong language to denounce the Russian threats, saying: "It is pathetic rhetoric. It is unhelpful and it leads nowhere."