US Defence Secretary Donald Rumsfeld has praised Vietnam's economic progress on a visit to discuss military relations with America's former enemy.
Security is dominating the agenda of Mr Rumsfeld's tour of Asia
He congratulated his Vietnamese counterpart, Pham Van Tra, on the country's "amazing economic achievements" of the last 11 years.
The two held talks on defence issues, but Mr Rumsfeld played down speculation the US was seeking new bases.
The two countries signed an important trade deal last week.
"Last night, after I arrived, I was able to take a short walk around Hanoi and feel the vibrancy and energy," said Mr Rumsfeld on Monday.
"There was a significant change in that short period of time."
'No wish list'
It is the first visit by a US defence secretary in six years, and only the second visit since the end of the Vietnam war in 1975.
Earlier, in Singapore, the US defence secretary said Washington had "no plans for access to military facilities in Vietnam".
"I don't have a wish list and I don't have a set of things that we're trying to achieve," he added.
The issue of US ties is sensitive for Vietnam, which needs to balance them against its relations with China, the BBC's Bill Hayton reports.
However, Vietnam is extremely wary of Beijing's regional ambitions and this is something which Hanoi and Washington can agree on, at least in private, our correspondent adds.
Unlike most official visitors to Hanoi, Mr Rumsfeld did not pay his respects at the mausoleum of Ho Chi Minh - the communist leader and founder of modern Vietnam.
He did, however, make time to visit the Temple of Literature, one of the city's oldest centres of learning.