A helicopter will fly low over the city until Sunday, testing radiation levels.
Blog Briefing Room
He said Reid's rhetoric about "domestic terrorists" could inflame tensions.
A quarter of those polled said the president rarely or never lies.
The Labour Party has hired "the strategist who masterminded" Barack Obama's election.
Ruth Bader Ginsberg and Antonin Scalia both think the programs will reach the high court.
Militants have largely taken over the city of Donestsk.
Simon & Schuster is publishing the book, set for release on June 10.
Obama did acknowledge that the issue is "hard politics" for many Republicans.
The former first daughter, 34, made the big reveal in New York City.