Senior American officials say NATO leaders have agreed to fully endorse US missile defense plans for Europe over Russian objections. Czech officials have also announced an agreement to install a radar tracking site for the system in their country. A joint statement issued Thursday on the sidelines of the NATO summit in Bucharest, Romania, says that the Czech Republic and the United States will sign a missile defense agreement in May. The NATO endorsement of the system is contained in a communique being adopted by alliance leaders.