President Bush mourned Ronald Reagan (search) on Saturday as a great American who "leaves behind a nation he restored and a world he helped save."
He called Reagan's death at his home in California "a sad hour in the life of America."
Bush ordered flags flown at half-staff on federal buildings for 30 days starting Sunday.
Bush, who is in France for D-Day (search) ceremonies, was notified of Reagan's death in Paris at about 4:10 p.m., EDT, by White House chief of staff Andy Card, who woke up the president at the U.S. ambassador's residence to deliver the news.
The president said he had talked to Reagan's widow, Nancy, and offered her the nation's prayers and condolences.
In remarks, Bush expressed the nation's thanks to Reagan for his contributions to the United States and the world.
Bush said Reagan "had the confidence that comes with conviction, the strength that comes with character, the grace that comes with humility, and the humor that comes with wisdom."
Secretary of State Colin Powell (search), with Bush in France, said Reagan "fueled the spirit of America" and that "the world and his fellow Americans will forever be in his debt."
The retired general, whose career got a big boost from Reagan when he was named national security advisor, said, "I was proud to be a soldier during his presidency as he restored the morale and fighting prowess of our Armed Forces."
Bush said that during the years of Reagan's presidency, the nation "laid to rest an era of division and self-doubt and because of his leadership the world laid to rest an era of fear and tyranny."
Reagan's two terms in office were marked by a thaw in the Cold War with the Soviet Union, a nation he had called the "Evil Empire, that had begun at the end of World War II.
Bush hastily summoned reporters to the residence of the U.S. ambassador in Paris where Bush was staying overnight in between meetings with French President Jacques Chirac and Sunday's D-Day ceremony in Normandy.
Bush walked somberly down an arcing staircase into a sitting room and assumed his position behind a lectern with the presidential seal.
He blinked back tears as he said this line: "He always told us for America the best is yet to come.
"We comfort ourselves in the knowledge that this is true for him too," Bush said. "His work is done. And now a shining city awaits him."
White House spokesman Scott McClellan declined to say whether Bush would keep his schedule for the G-8 summit meeting (search), set to begin Tuesday in Sea Island, Ga., and declined to say whether he had alerted the foreign leaders about a Reagan funeral.
McClellan, who said that Bush would attend a Reagan memorial service, called the former Republican president someone Bush "greatly admired for his leadership and his vision and the way he set clear priorities."