Fresh sanctions slapped by the United States are meant to "expose and disrupt" links between Iran, Hizbullah movement and Syria, U.S. Secretary of State Hillary Clinton said Saturday.

She said the "number one goal" of Washington and Ankara was to hasten the end of Bashar Assad's regime in Damascus and stop the bloodshed, while warning that Syria must not become a haven for Kurdish rebels battling Turkey.

The United States Wednesday denounced Syrian President Bashar Assad as "cowardly" and "despicable" for calling on his forces to continue the fight against opposition rebels.

"We think it's cowardly quite frankly to have a man who's hiding out of sight be exhorting his armed forces to continue to slaughter the civilians of his own country," said a U.S. State Department spokesman, Patrick Ventrell.

Sizzling high temperatures punished much of the eastern United States again on Saturday, one day after hurricane-like thunderstorms killed at least 11 people and cut power supply to millions.

Thermometers brushed the 100 degree Fahrenheit (37.7 Celsius) mark from the Mississippi River to the Mid-Atlantic coast as a vast area of high pressure squatted over the southern states with no signs of moving on soon.

Former U.N. chief Kofi Annan, the author of a fledgling peace plan on Syria, called Friday for "additional pressure" in the wake of a new massacre as he held talks in the United States.

Opening a meeting with US Secretary of State Hillary Clinton, the U.N.-Arab League envoy said he would discuss "how we can put additional pressure on the government and the parties to get the plan implemented."

The United States endorsed Wednesday the Arab League's proposal to invoke the United Nations' tough Chapter VII sanctions against the Syrian regime.

But Washington held off from supporting Chapter VII's powers to initiate a military intervention and focused on economic sanctions against Syrian President Bashar Assad's embattled government.

A U.S. State Department team will visit Moscow this week to discuss the Syria crisis, a top official said Tuesday as Western pressure mounted on Russia to back new action against its Soviet-era ally.

"We are in the process of meeting (U.S. Secretary of State) Hillary Clinton's deputies who work on the Middle East and Syria in particular," Russia's Deputy Foreign Minister Mikhail Bogdanov told the RIA Novosti state news agency.

Syrian President Bashar Assad was lying when he denied his regime had any involvement in the massacre of more than 100 civilians near the central town of Houla, the White House said Monday.

Asked if Assad lied at the weekend when he denied his forces fired on innocent civilians near Houla, President Barack Obama's spokesman, Jay Carney, said: "Yes.

Chinese Premier Wen Jiabao on Friday asked Secretary of State Hillary Clinton to respect differences between the two countries, as U.S. officials scrambled to resolve a row over a dissident.

Wen welcomed Clinton and Treasury Secretary Timothy Geithner to the ornate Purple Light Pavilion of Zhongnanhai, the Chinese leadership's compound in the heart of Beijing.

Chinese activist Chen Guangcheng has left the U.S. embassy to seek medical care and join his family, officials said Wednesday, in a dramatic turn in a standoff between the Pacific powers on the eve of key talks.

Hours after Secretary of State Hillary Clinton arrived in China for long-planned meetings, the U.S. broke nearly a week of silence over Chen's case and said that the dissident has been taken for treatment in Beijing.

Pakistan's intelligence service believes it deserves credit for helping U.S. spy agencies locate the hideout of Osama bin Laden, who was killed by U.S. commandos nearly a year ago, The Washington Post reported.

"The lead and the information actually came from us," an unnamed senior official with Pakistan's Inter-Services Intelligence Directorate (ISI) told The Post.