Germany's federal prosecutors said Wednesday they had opened an investigation over alleged snooping on Chancellor Angela Merkel's mobile phone by the U.S. National Security Agency in a case that has soured relations.

The long-anticipated probe, which follows an explosive allegation last year that U.S. spies had eavesdropped on Merkel's mobile phone conversations in the past, is against persons unknown, chief federal prosecutor Harald Range said.

An American fighting for a hardline Islamist group carried out a deadly suicide bombing, U.S. officials said Friday, in the first such case in the war.

The confirmation came amid growing fears over the flood of foreigners into Syria, with no end in sight in the three-year war that has already left 162,000 people dead.

U.S. Defense Secretary Chuck Hagel on Saturday urged Thailand's coup leaders to release detainees and call for elections immediately.

"We urge the Royal Thai Armed Forces to release those who have been detained, end restrictions on free expression, and move immediately to restore power to the people of Thailand, through free and fair elections," Hagel said at a top Asian security conference in Singapore.

Sudan has carried out "unconscionable" violence including aerial strikes and aggression against civilians in its war-torn regions, the U.S. special envoy to the country charged Thursday.

A senior official from the ruling party in Khartoum disputed the allegation and said the envoy, Donald Booth, was not qualified to make such comments.

The U.S. Navy is sending a guided missile cruiser to the Black Sea, the Pentagon said Tuesday, the latest bid by Washington to to reassure allies worried over Russia's intervention in Ukraine.

"I can confirm the Vella Gulf, a Navy cruiser, will be going in to the Black Sea probably later this week," Pentagon spokesman Rear Admiral John Kirby told reporters.

Brunei would violate international standards on human rights if the oil-rich sultanate presses ahead with stoning and other punishments under sharia law, an incoming U.S. official said Thursday.

Nina Hachigian, nominated to be the U.S. ambassador for the 10-nation ASEAN bloc, told her Senate confirmation hearing that it was "important that a nation's laws conform with its international obligations on human rights."

The United States on Wednesday promised to keep up military cooperation with Georgia, a former Soviet state that views the escalating crisis in Ukraine with deep concern.

During a meeting with his Georgian counterpart Irakli Alasania, Defense Secretary Chuck Hagel "reaffirmed the importance of the U.S. partnership with Georgia, and pledged to continue our strong defense cooperation," Pentagon spokesman Rear Admiral John Kirby said.

The leader of the Syrian opposition Ahmad Jarba on Wednesday called on the U.S. to give his forces the weapons necessary to defeat the regime's well-armed military.

Opposition forces need "efficient weapons to face these attacks including air raids, so we can change the balance of power on the ground," Jarba told a U.S. think-tank at the start of his first official visit to Washington. 

The U.S. government conveyed a clear message to the Lebanese government asking it not to facilitate the voting process of thousands of Syrians living in Lebanese territories in the Syrian elections slated next month, a U.S. diplomat told As Safir daily on Tuesday on condition of anonymity.

“Lebanon's interior minister is required not to issue any supportive statement on behalf of the Lebanese government backing the elections, which comes in commitment to the Baabda Declaration and the dissociation policy adopted by the cabinet since the mandate of PM Najib Miqati,” the source said.

In a boost to the Syrian opposition, Washington has recognized its offices in the United States as diplomatic missions, U.S. officials said Monday, as the movement's chief prepares for high-level talks here.

Ahead of the first official visit by the head of the Syrian National Coalition, Ahmad Jarba, the move aims "to empower the Syrian moderate opposition," a senior U.S. administration figure told reporters.