The carrier, which is owned by property and leisure company FLC Group and made its first flights in January, placed a provisional order last year for 20 Boeing 787 widebody jets worth $5.6 billion (4.3 billion pounds) at list prices.
"We will sign with Boeing a deal to buy 10 more Boeing 787s. This is different from the deal signed earlier for 20 Boeing planes," said the executive who declined to be named due to the confidentiality of the matter.
"That means we will have ordered 30 Boeing 787s. The deal will be signed during the summit," the executive said.
"This is a firm order valued at nearly $3 billion," added the executive. Boeing had no immediate comment.
Bamboo is currently operating 10 Airbus planes.
Bamboo is aiming to open routes to the United States after the U.S. Federal Aviation Administration declared Vietnam complied with international aviation standards, in a move that would allow Vietnamese carriers to fly there for the first time and codeshare with U.S. airlines.
U.S. President Donald Trump and North Korean leader Kim Jong Un will hold their second summit in the Vietnamese capital of Hanoi on Feb. 27-28.
Bamboo's first 787 is set to arrive in the third quarter of 2020 and the airline is preparing to launch flights to the United States from late 2019 or early 2020 with leased jets unless Boeing can deliver them earlier, Bamboo's chairman Trinh Van Quyet had earlier told Reuters.
"Direct flights between Vietnam and the U.S. will not only push tourism activities, but also further facilitate bilateral trade and investment," he said. "We are receiving huge support from Boeing to deploy our flights to the U.S."
Rivals Vietnam Airlines JSC and VietJet Aviation JSC also have ambitions to fly to the United States, although the latter carrier has yet to place an order for widebody jets.
VietJet is also expected to sign a major jet deal with Boeing on the sidelines of the Trump-Kim summit, according to sources familiar with the matter.
VietJet, while not government-owned, increasingly uses state visits to showcase major plane orders balanced between Boeing and Airbus SE. It signed a deal to buy 100 Boeing 737 MAX narrowbody jets when former U.S. President Barack Obama visited Hanoi in 2016.
The airline is likely to finalise next week a separate provisional deal agreed last year at the Farnborough Airshow to buy another 100 Boeing 737 MAX jets worth almost $13 billion at list prices, sources said on condition of anonymity.
(Reporting by Khanh Vu in Hanoi; Additional reporting by Tim Hepher in Paris, Writing by Jamie Freed; Editing by Keith Weir)
By Khanh Vu