U.S. President Barack Obama on Wednesday invited German Chancellor Angela Merkel to Washington in an effort to mend fences after a diplomatic crisis provoked by revelations of U.S. eavesdropping on her mobile phone.

Obama called Merkel to wish her a speedy recovery after her recent skiing injury and invited her to visit at a "mutually agreeable time in the coming months," the White House said in a statement.

President Barack Obama's "team of rivals" first-term cabinet has come back to haunt him, following surprisingly blunt critiques of his leadership and top aides by ex-Pentagon boss Robert Gates.

Gates, the Washington Republican lifer who served six presidents in senior national security jobs, sent political shockwaves through Washington after his unsparing assessments of the Obama administration in his new book, leaked to top newspapers.

Former Defense Secretary Robert Gates asserts in a new memoir that President Barack Obama grew frustrated with U.S. policy in Afghanistan and that Vice President Joe Biden has been wrong on nearly every foreign policy and national security issue. He also accuses members of Congress of inquisition-like treatment of administration officials.

Obama approved the strategy of putting 30,000 additional troops into Afghanistan and placing Gen. David Petraeus in charge, even though some top advisers opposed the so-called surge he announced in December 2009.

U.S. President Barack Obama late Saturday ended his vacation in sunny Hawaii and boarded Air Force One for a flight back home to chilly Washington.

Obama arrived in his native Hawaii on December 21 along with his wife Michelle and daughters Sasha, 12, and Malia, 15.

Israeli MPs handed President Shimon Peres a petition on Wednesday urging the United States to release imprisoned Israeli spy Jonathan Pollard, after reports Washington spied on its own allies.

"Pollard has served 29 years in prison for the severe offences he committed," reads the petition, which was signed by 106 of the 120 members of the Israeli parliament and addressed to U.S. President Barack Obama. "The conditions have ripened for his release."

President Barack Obama Thursday signed into law the compromise U.S. budget bill recently negotiated by feuding lawmakers and a massive defense bill that takes a step toward ultimate closure of Guantanamo.

After signing the legislation while vacationing in Hawaii with his family, Obama praised the National Defense Authorization Act for allowing accelerated repatriation of detainees from the U.S. naval facility at Guantanamo Bay, Cuba.

Just six months after first leaking National Security Agency secrets in a move that triggered a revaluation of U.S. surveillance policies, Edward Snowden is declaring "mission's already accomplished."

Snowden told The Washington Post in his first in-person interview since his June arrival in Russia, which granted him temporary asylum, that he was satisfied because the public is now informed about the U.S. government's massive sweep of Internet and phone records.

U.S. President Barack Obama has symbolically signed up for health insurance to promote his own controversial health care reform legislation, a White House official said Monday.

The official said Obama -- on vacation with his family in Hawaii for the holidays -- signed up over the weekend for "a health care plan made available by the Affordable Care Act on the DC marketplace."

The United States -- a key backer of South Sudan's 2011 independence -- is increasing diplomatic pressure amid an intensifying conflict there but will not consider military intervention, experts said.

Analysts do not expect Washington to launch a massive military campaign, despite President Barack Obama's decision to send nearly 100 troops to the country this week to help protect U.S. citizens, personnel and property.

Cuban President Raul Castro warned Saturday his country could remain estranged from the United States for decades if Washington does not drop political demands.

"If we really want to make progress in bilateral relations, we have to learn to respect each other's differences and get used to living peacefully with them. Otherwise, no. We are ready for another 55 years like this," Castro said at the legislature's closing session.