HANOI (Reuters) -Vietnam will buy more American goods, including defence and security products, and has asked for a 45-day delay in the imposition of U.S. tariffs, Prime Minister Pham Minh Chinh said in a statement issued late on Monday.

Hanoi will also seek faster deliveries of commercial planes that Vietnamese airlines have ordered from the U.S., Chinh said at a cabinet meeting late on Monday.

The Southeast Asian country, a major regional manufacturing base for many Western companies, last year had a trade surplus of more than $123 billion with the U.S., its largest export market.

Chinh said Vietnam had asked the U.S. to delay the 46% tariff rate that U.S. President Donald Trump announced last week to allow time for negotiations.

Vietnam was seeking to "negotiate with the U.S. side for balanced and sustainable trade, in line with the interests of the two sides," the statement said.

White House trade adviser Peter Navarro highlighted major concerns on Monday, including transhipping from China, the dumping of seafood and other goods, and intellectual property issues.

"They engage in intellectual property theft," Navarro told CNBC, regarding Vietnam. "They have the biggest number of cases aside from China at the Department of Commerce on the dumping."

In Monday's statement, Chinh said Vietnam would review issues such as its monetary policy, exchange rate, non-tariff barriers and ensuring the correct origin of goods, in line with the concerns aired by Navarro.

In a statement on Tuesday, following a tariff task force meeting, the government said Vietnam was also considering adjustments to its current bilateral trade agreement with the United States, adding content on tax and intellectual property.

The country's benchmark stock index has fallen nearly 14% since Trump's announcement of the tariffs on April 2. The index fell 6.26% to 1,135 in early trade on Tuesday.

On Friday, Trump and Vietnam's leader To Lam agreed to discuss a deal to remove tariffs, both leaders said after a telephone call that Trump described as "very productive".

Since an arms embargo was lifted in 2016, U.S. defence exports to Vietnam have been largely limited to coastguard ships and trainer aircraft.

Last year sources said there were talks on sales of Lockheed Martin C-130 Hercules military transport planes to Hanoi.

(Reporting by Khanh Vu, additional reporting by Phuong Nguyen; Editing by Kate Mayberry and Clarence Fernandez)