During a historic stop in Japan at the end of this week, President Obama will restate a message he voiced in Eastern Europe three months after taking office in 2009 -- a call to rid the world of nuclear arms. This time, he speaks Friday at Hiroshima (pronounced HEAR-oh-sheema), where the first atomic weapon was used in war. Until now, no current American president has visited the city where a U.S. Air Force B-29 dropped a bomb in 1945, killing up to 146,000 people in a successful effort to end World War II.

American and Japanese officials say the visit to a 30-acre Peace Memorial Park doesn’t amount to an apology for a decision by President Harry Truman, designed to force Japan's surrender. Prime Minister Shinzo Abe, who’ll accompany his guest there after a seven-nation economic summit on a Japanese island, describes the visit as a chance to honor Hiroshima victims and support nuclear disarmament. On the U.S. side, presidential adviser Benjamin Rhodes says the president "will not revisit the decision to use the atomic bomb at the end of World War II. Instead, he will offer a forward-looking vision focused on our shared future."

Obama’s 10th trip to Asia as president began this past weekend in Vietnam, a Communist country where he hadn’t been until now. He's meeting with government leaders in Hanoi, the capital, and will speak there about U.S.-Vietnam relations. The two countries fought a long, bloody war in the 1960s and first half of the 1970s. The government, concerned about aggressive moves by neighboring China, would like to buy U.S. weapons – something now blocked by a decades-old embargo on arms sales to the former enemy.

White House says: "The President will make an historic visit to Hiroshima . . . to highlight his continued commitment to pursuing the peace and security of a world without nuclear weapons." – Josh Earnest, presidential press secretary

Japanese leader says: "Japan is the only country to be hit by a nuclear weapon, and we have a responsibility to make sure that terrible experience is never repeated anywhere." -- Abe, prime minister

Disarmament activist says: "We would like to see [Obama] take some action with this visit so that it's not just empty words." -- Paul Kawika Martin of Peace Action group in suburban Washington., D.C.