US Secretary of State Hillary Clinton is to become the first top US diplomat to visit Laos in 57 years, as part of an eight-nation tour that also takes her to Egypt and Israel, the State Department announced on Thursday.

"Clinton will travel to France, Japan, Mongolia, Vietnam, Laos, Cambodia, Egypt and Israel departing Washington DC on July 5," said a statement from State Department spokeswoman Victoria Nuland released upon their departure.

Clinton was officially invited to Laos by counterpart Foreign Minister Thongloun Sisoulith in 2010 when he made the first visit by a top Laotian official to Washington since rebels swept to power and replaced the monarchy there in 1975.

US relations with Laos, while never severed, were long tense, in part over its campaign against the Hmong Hill people who assisted US forces during the Vietnam War, along with uncertainties over American troops missing in action.

But the United States established normal trade ties with Laos in 2004 and has recently looked at ways to help clean up abandoned ordnance that continues to take a heavy civilian toll.

US forces dropped millions of bombs on the country to cut off supply lines, which according to a 2010 survey have killed or injured some 50,000 people in Laos.

AFP-Xinhua