By Guy De Launey
BBC News, Phnom Penh
The United States is opening its first purpose-built embassy in Cambodia on Tuesday.
The new US embassy is prominent in the capital
The new facility is one of the most prominent buildings in Phnom Penh, with a staff of more than 500.
Recently the US resumed military aid to Cambodia for the first time since the Vietnam war, indicating an increasing involvement in the country.
The new embassy is hard to miss. Its black, white and red marble structures occupy an entire block.
It is next to Wat Phnom, the landmark temple which gave Phnom Penh its name.
And while other major embassies in the city are hidden behind towering walls, the US facility makes do with a set of railings. If the plan was to make an impression, it has succeeded.
The US has had a somewhat ambivalent relationship with Cambodia since its return to peace in the 1990s. But everything about the embassy says the superpower is now keen to be involved here.
Some have speculated that the US is trying to counter the increasing influence of other powers in the region. China is now the biggest investor in Cambodia and also provides extensive military aid.
The US has insisted that is not a major concern. But embassy spokesman Jeff Daigle said increased involvement was likely.
"We are ready for expansion and several different agencies have expressed an interest in coming here and opening up offices.
"The bilateral relationship between the US and Cambodia has certainly been growing and deepening and expanding, and so some of these new offices coming in will just be another part of that expansion of the relationship," he said.
That includes assistance to the Cambodian armed forces. For the first time since the fall of the Khmer Rouge, US military advisers have been working with local troops.
But the US says it will continue to press Cambodia to improve its record on issues like human trafficking and human rights.