The meeting came after the United States on Saturday, at a defense conference in Singapore, called for an immediate end to all such work in the disputed waters where both Vietnam and Beijing have reclaimed land.

"The US and Vietnam are working together to ensure peace and stability in this region and beyond," Carter told reporters Monday at a press conference in Hanoi after holding talks on regional maritime disputes with his counterpart, Vietnamese Defense Minister Phung Quang Thanh.

Though he didn't reveal Hanoi's position on the issue, Thanh insisted its activities were not an attempt at expansion.

"We have some activities to enhance and consolidate the islands that are under our sovereignty," Thanh told reporters. "We do not expand the islands, we just consolidate to prevent erosion because of waves."

He noted that Vietnam has soldiers on its 21 islands and reefs.

China, on the other hand, claims nearly all of the South China Sea and is locked in territorial disputes with Vietnam as well as Brunei, Malaysia, the Philippines and Taiwan.

Carter pledged $18 million (16.4 million euros) on Monday to help Vietnam buy US-made Metal Shark patrol boats. He also hailed progress that had been made in a bilateral relationship that marks two decades this year since the US and Vietnam normalized ties in 1995.

Carter is in Vietnam as part of an 11-day trip to Asia.

av/cmk (AFP, dpa)