Obama says 'seeds of hate' must not take root

FILE - In this April 13, 2012, file photo President Barack Obama in Tampa, Fla., speaks about trade before heading to the Summit of the Americas. Obama will clinch the Democratic nomination for president Tuesday, April 24, ending a low-key primary race that many Americans probably didn't realize was happening. He's certain to reach the 2,778 delegates needed to secure his party's nod when five states vote on Tuesday. (AP Photo/Carolyn Kaster, File)

WASHINGTON (AP) — President Barack Obama says atrocities against peoples across the globe begin with daily ignorance and intolerance and that the world must not allow such "seeds of hate" to take root again.

Obama spoke at the U.S. Holocaust Memorial Museum, his first such appearance as president. He was announcing a plan to impose sanctions against foreign entities, chiefly Iran and Syria, who use technology to crackdown on dissidents.

Obama broadly defended his government's steps to halt mass killings during his three-plus years in office.

He said "we have saved countless lives."

In a warning to other nations, the president said that national sovereignty is never a license to "slaughter your people."