Republican White House hopeful Mitt Romney is losing favor among U.S. voters just three months ahead of his tough election battle with President Barack Obama, a new poll showed Wednesday.

The Washington Post-ABC News poll showed that 49 percent of voters have a negative view of the former Massachusetts governor, up from 45 percent in May.

NASA opened a new chapter in the history of interplanetary exploration on Monday when its $2.5 billion nuclear-powered robot Curiosity beamed back pictures from the surface of Mars.

The one-ton mobile lab is the largest rover ever sent to Mars, and its high-speed landing was the most daring to date, using a rocket-powered sky crane to lower the six-wheeled vehicle gently to the Red Planet's surface.

U.S. President Barack Obama welcomed an oil sharing deal Saturday between Sudan and South Sudan, which has helped resolve a dispute that nearly brought the rivals to war earlier this year.

Landlocked South Sudan said it had agreed to pay a pipeline transit fee of $9.48 per oil barrel to transport its crude through Sudan, a significant drop from Khartoum's initial demands of up to $36 a barrel in fees.

U.S. President Barack Obama on Thursday approved an extra $12 million in U.S. lifesaving humanitarian aid to Syrians to mitigate what he said were President Bashar Assad's "horrific atrocities."

The grant brings to $76 million the total amount of food, water, medical supplies, clothing, hygiene kits and other aid to some of the 1.5 million people in need in Syria, the White House said in a statement.

President Barack Obama has signed a covert document authorizing U.S. support for Syrian rebels locked in a battle to overthrow beleaguered President Bashar Assad, reports said Wednesday.

The directive was contained in a "finding" -- a device authorizing clandestine action by the Central Intelligence Agency, NBC and CNN said, citing unidentified sources.

U.S. President Barack Obama has for the first time hit the 50 percent mark in three crucial swing states, with women strongly favoring him over Republican foe Mitt Romney, a poll released Wednesday said.

With fewer than 100 days until the November 6 election, the Quinnipiac University/CBS News/New York Times survey gave Obama a majority of the vote in Florida (51 percent) and Pennsylvania (53 percent), and 50 percent in Ohio.

White House hopeful Mitt Romney on Sunday held top-level talks in Israel about how to handle fears over Iran's nuclear ambitions, on a visit aimed at burnishing his foreign policy credentials.

"Like you, we are very concerned about the development of nuclear capabilities on the part of Iran and feel it is unacceptable for Iran to become a nuclear armed nation," Romney told reporters on meeting President Shimon Peres.

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.

U.S. President Barack Obama made a show of support for Israel at the White House on Friday, ahead of a weekend visit to the U.S. ally by Republican presidential rival Mitt Romney.

Surrounded in the Oval Office by representatives of the pro-Israel lobby AIPAC and by U.S. lawmakers, Obama signed a law reinforcing U.S. security and military cooperation with Israel.

President Barack Obama extended for another year Wednesday sanctions against entities the U.S. considers threatening to Lebanon's stability, a veiled reference to supporters of Hizbullah.

Obama said in a message to Congress that he would prolong the "national emergency" which former president George W. Bush first declared in 2007, and which has been renewed each year since.