German Chancellor Gerhard Schroeder has described Pope Benedict XVI as a worthy successor to John Paul II and said his election to lead the Roman Catholic church was a great honour for Germany.
"That the new Pope Benedict XVI comes from Germany, that is a great honour for our whole country," Schroeder said in a brief news conference.
"In Pope Benedict XVI, a pope has been chosen who knows the world Church like no one else. He is a great, world-renowned theologian. Pope Benedict XVI is a worthy successor to Pope John Paul II."
He added he looked forward to welcoming him to World Youth Day, a Catholic youth rally to be held in Cologne in August.
President George W. Bush praised the choice of the conservative cardinal, calling him a "man of great wisdom and knowledge."
"He's a man who serves the Lord," Mr Bush told reporters at the White House.
"I offer Your Holiness, on the assumption of your high office, congratulations and my very best wishes for the success of your Pontificate," Mr Blair said.
"I look forward to continuing our cooperation with the Holy See on issues of international importance such as Africa and development."
British Prime Minister Tony Blair also sent a message of congratulations to the new Pope.