President Obama

Obama is the first sitting U.S. president to visit the city destroyed by an American atomic bomb in the closing days of World War II.

Following a gruesome killing, allegedly by a former Marine, controversy over the presence of American troops on Okinawa is adding another layer to Obama's historic trip this week.

During a visit to Hanoi, President Obama announced an end to the five-decades-long ban on selling weapons to Vietnam.

Graduations are always milestones for the students. This year they're a milestone for the president, too, as he begins to look towards his own graduation from the Oval Office.

Some applauded the president's speech at the historic black university as a break from "respectability politics" that demean African-Americans. Other saw it as more of the same.

President Obama will be the first sitting U.S. president to visit the Japanese city since America dropped an atomic bomb on Hiroshima and Nagasaki at the end of 1945.

The president says he hopes to meet Mari Copeny on May 4 when he goes to Flint. She wrote to tell him about her activism on behalf of children affected by the city's contaminated water.

Among them: Two incumbent Pennsylvania congressmen are on the defense amid questions about their ethics and personal relationships; and Maryland candidates for Senate are divided by race and gender.

The president's announcement, set to be delivered Monday in Germany, will bring the total number of American military personnel deployed in the country to as many as 300.

Twenty-six states are challenging the action, which would grant temporary, quasi-legal status and work permits to as many as 4 million parents who entered the U.S. illegally before 2010.

The White House hasn't announced any such plans. But Obama will be in Japan next month and a visit would be a grand symbolic gesture in keeping with his emphasis on nuclear nonproliferation.

President Obama said stopping attacks like those in Brussels is "difficult work." His advisers, he said, are working on "every strategy possible."