U.S. President Barack Obama imposed new economic sanctions Tuesday targeting Iran's oil export sector and a pair of Chinese and Iraqi banks accused of doing business with Tehran.

In a statement released by the White House, Obama said the new measures underlined the United States' determination to force Tehran "to meet its international obligations" in nuclear negotiations.

A Chicago man pleaded guilty Monday to attempting to provide support to a designated terrorist organization by traveling to Somalia to join the Shabab, prosecutors said.

Shaker Masri, 28, was born in Alabama and lived in Chicago's upscale Gold Coast neighborhood prior to his 2010 arrest, hours before he was scheduled to travel to Somalia.

Prosecutors charged grad school dropout James Holmes on Monday with killing a dozen people and trying to slay scores more in one of the worst mass shootings in U.S. history.

The 24-year-old neuroscience student allegedly burst into a midnight viewing of the latest Batman film, "The Dark Knight Rises," then opened fire into the packed auditorium with a high-powered assault rifle.

The United States has slashed a signature Iraqi police training program as it downsizes its massive diplomatic mission amid high costs and negative Iraqi sentiment, a U.S. watchdog said on Monday.

The Special Inspector General for Iraq Reconstruction said in a report on an audit it conducted that the United States had wasted some $206 million on building facilities for the Police Development Program (PDP), which a top Iraqi interior ministry official has termed "useless."

U.S. defense chief Leon Panetta sets off on an international tour Monday that, after Tunis and Cairo, takes him to Israel and Jordan, in a region that feels threatened by Iran's nuclear program and potential spillover from troubled Syria.

In Jerusalem, the secretary of defense will discuss regional issues with his Israeli counterpart Ehud Barak, among other leaders of the Jewish state.

Flooding across impoverished North Korea this month has killed 88 people, left tens of thousands homeless and devastated swathes of farmland, state media said Saturday.

A week of floods "caused by typhoon and downpour... claimed big human and material losses", Pyongyang's official news agency said. The new death toll was a dramatic increase from the figure of eight reported Wednesday.

Israeli Defense Minister Ehud Barak thanked U.S. President Barack Obama for his decision to reinforce security and military cooperation with the Jewish state, his office said on Saturday.

"Mr. Barak welcomes President Obama's decision to sign a law reinforcing cooperation in defense affairs between America and Israel, including the decision to grant an extra $70 million in aid towards the 'Iron Dome' project," his office said in a statement.

The U.S. Senate unanimously passed a resolution urging the State Department to put the Haqqani network, which operates in Afghanistan and Pakistan, on the U.S. list of terrorist groups.

The late Thursday voted followed the passing of a resolution in the House of Representative last week. It now requires President Barack Obama's signature to enter into force.

U.S. presidential hopeful Mitt Romney tried to put the fuss caused by his criticism of London's Olympic preparations behind him Friday, admitting that the British capital now seems ready for the games.

The Republican challenger, who will face off against President Barack Obama in November's U.S. election, offended many in Britain on Thursday when he began a visit to London by expressing concern about the host city's readiness.

An Iranian-born U.S. man pleaded guilty Thursday to attempting to smuggle missile components from the United States to Iran, prosecutors said.

"Our national security is threatened when anyone attempts to illegally export restricted military components that could fall into the wrong hands," said Gary Hartwig, special agent in charge of Homeland Security Investigations (HSI) in Chicago.