Phnom Penh - US Deputy Secretary of State John Negroponte flew into the northern Cambodian tourist hub of Siem Reap in a relaxed start to his three-day official visit, touring the ancient temples of Angkor Wat, local officials said on Sunday.

Negroponte arrived in Cambodia from neighbouring Vietnam for a visit which will include meetings with Prime Minister Hun Sen and an array of ministers including Foreign Minister Hor Namhong.

He is scheduled to sign a 24-million-dollar agreement on Monday to assist economic development in the country and will hold a press conference on Tuesday morning before flying out, according to a schedule from the US embassy.

At Angkor Wat, Negroponte toured the 12th century World Heritage- listed temples, which are also the nation's largest tourism draw, 300 kilometres from the capital, and he is expected to arrive in Phnom Penh early on Monday morning, officials said.

Ties between the US and Cambodia have warmed considerably in recent years, with the US providing support for the nation's armed forces as well as recently agreeing to give aid directly to the government, rather than through other agencies.

Cambodia has also been praised by the US for its help in fighting terrorism and its assistance in helping locate the remains of US soldiers missing in action, mostly from the Vietnam War era.(dpa)