A top Chinese official has warned of a "trust deficit" between Beijing and Washington and expressed hopes that a key visit to the United States next week by China's leader-in-waiting will strengthen ties.

Vice Foreign Minister Cui Tiankai made the remarks in a speech published on the ministry's website on Tuesday, as Beijing and Washington lock horns over China's decision to veto a U.N. resolution on the bloody violence in Syria.

A senior Treasury Department official will travel to Russia and the Middle East for talks about sanctions on Syria and Iran, the U.S. government said Monday, days after Moscow vetoed U.N. action against Damascus.

The Treasury Department's assistant secretary for terrorist financing Daniel Glaser will visit Doha, Muscat and Moscow from February 6-10.

U.S. President Barack Obama on Monday ordered new sanctions into force on Iran, including its central bank, seeking to tighten a choke hold on Tehran's economy as a nuclear showdown deepens.

Obama signed an executive order implementing parts of a new sanctions regime passed by Congress late last year at a time of high tensions with Iran and rampant speculation about a possible Israeli strike against its nuclear sites.

China on Monday denied U.S. accusations it was protecting the Syrian regime, after drawing international criticism for vetoing a U.N. resolution condemning a deadly crackdown on protests by Damascus.

Beijing called on both sides in the conflict to halt violence, after U.S. Secretary of State Hillary Clinton accused China and Russia of "protecting the brutal regime in Damascus", calling their veto of the resolution a "travesty".

Hundreds of protesters demonstrated Saturday in New York and pacifist groups took to the streets in dozens of other U.S. and Canadian cities in a "Day of Mass Action" against a possible war with Iran.

About 500 protesters gathered in Manhattan's Times Square and marched to the headquarters of the U.S. mission to the United Nations and to the Israeli consulate.

President Barack Obama on Saturday accused Syrian President Bashar Assad's government of murdering civilians in an "unspeakable assault" in the city of Homs, and demanded that Assad step down.

"Assad must halt his campaign of killing and crimes against his own people now. He must step aside and allow a democratic transition to proceed immediately," Obama said in a statement.

U.S. health authorities on Friday urged all boys age 11-12 to get a routine vaccination against the most common sexually transmitted disease, human papillomavirus, or HPV.

Other changes as part of an annual update to U.S. immunization schedules included a recommended hepatitis B vaccine to the protect the livers of adults up to age 60 who have diabetes and a vaccine against whooping cough for pregnant women.

A major U.S. breast cancer foundation Friday reversed its decision to stop funding Planned Parenthood after outcry over the move sparked a political and fundraising backlash by women's health advocates.

The Susan G. Komen for the Cure Foundation issued a statement saying it was sorry and would continue to give money to help underwrite breast screening at Planned Parenthood clinics, which amounted to $680,000 last year.

Two American women and their Egyptian tour guide, who were captured by armed Bedouins in the Sinai peninsula on Friday, have been released unharmed after several hours, security officials said.

The three arrived back at their hotel in the Red Sea resort of Sharm el-Sheikh, where they were met by South Sinai's governor and security chief, officials said.

U.S. Defense Secretary Leon Panetta believes there is a "strong likelihood" that Israel will strike Iran's nuclear installations this spring, the Washington Post said Thursday in an editorial.

When asked about the opinion piece by reporters travelling with him to a NATO meeting in Brussels, Panetta brushed it aside.