Korean Air on Tuesday said it will purchase more than 100 Boeing aircraft in the largest deal in South Korea's aviation history, just hours after the country's president met US President Donald Trump in Washington.

"Korean Air announced its intent to purchase 103 next-generation aircraft from Boeing," the company said in a statement.

The purchase, which also includes spare engines from GE Aerospace, is valued at approximately US$50 billion according to the company, and the aircraft are scheduled for delivery "through the end of 2030".

"The aircraft purchase order includes 20 Boeing 777-9s, 25 Boeing 787-10s, 50 Boeing 737-10s, and eight Boeing 777-8F freighters," the Seoul-based carrier added.

The agreement was signed in Washington on Monday during a meeting of Korean and US businesses, overseen by Commerce Secretary Howard Lutnick and South Korea's Ministry of Trade, Industry and Energy.

Trump held on the same day his first meeting with South Korean President Lee Jae-myung to discuss bilateral relations, just weeks after both countries agreed to trade deals involving announcements of huge investments into the United States.

Korean Air had agreed in March to purchase up to 50 Boeing aircraft, a deal valued at around US$32 billion, which also involved GE Aerospace.

Boeing has been hit by manufacturing backlogs and safety concerns.

A total of 241 people on board the London-bound Boeing 787 Dreamliner were killed when the plane crashed shortly after take-off from Ahmedabad in western India on June 12.

A preliminary investigation report by India's Aircraft Accident Investigation Bureau said fuel to the jet's engines was cut off moments before impact.

After the crash, India and Singapore ordered their airlines to examine fuel switches on several Boeing models. (AFP)