Lotte is one of the South Korean companies tapping into the fast-growing middle class of Vietnam.

Vietnamese Prime Minister Nguyen Xuan Phuc said on Tuesday he would sign deals for U.S. goods and services worth $15 billion to $17 billion during his visit to Washington, D.C., mainly for high technology products and for services.

"Vietnam will increase the import of high technologies and services from the United States, and on the occasion of this visit, many important deals will be made," Phuc told a U.S. Chamber of Commerce dinner.

Phuc, who is due to meet with U.S. President Donald Trump on Wednesday at the end of a three-day visit to the United States, did not provide any further details of the transactions.

GE Power Chief Executive Officer Steve Bolze told the dinner that General Electric Co will sign new business worth about $6 billion with Vietnam, but also offered no details.

Phuc's comments came after U.S. Trade Representative Robert Lighthizer expressed concern about the rapid growth of the U.S. trade deficit with Vietnam, saying this was a new challenge for the two countries and he was looking to Phuc to help address it.

"Over the last decade, our bilateral trade deficit has risen from about $7 billion to nearly $32 billion," Lighthizer said. "This concerning growth in our trade deficit presents new challenges and shows us that there is considerable potential to improve further our important trade relationship."

Lighthizer and other Trump administration trade officials have pledged to work to reduce U.S. bilateral trade deficits with major trading partners. The $32 billion deficit with Vietnam last year -- the sixth largest U.S. trade deficit -- reflects growing imports of Vietnamese semiconductors and other electronics products in addition to more traditional sectors such as footwear,

apparel and furniture.

The trade issue has become a potential irritant in a relationship where Washington and Hanoi have stepped up security cooperation in recent years given shared concerns about China's increasingly assertive behavior in East Asia.

Phuc's meeting with Trump makes him the first southeast Asian leader to visit the White House under the new administration.

It reflected calls, letters, diplomatic contacts and lower-level visits that started long before Trump took office in Washington, where Vietnam retains a lobbyist at $30,000 a month.

Vietnam was disappointed when Trump ditched the 12-nation Trans-Pacific Partnership (TPP) trade pact, in which Hanoi was expected to be one of the main beneficiaries, and focused U.S. trade policy on reducing deficits.