Hanoi - Malaysian Prime Minister Najib Razak thanked Vietnam during an official visit to Hanoi on Friday for its help in the search for flight MH370.
The Malaysia Airlines Boeing 777 went missing as it was about to enter Vietnamese airspace nearly four weeks ago.
"I would like to place on record our sincere appreciation of the Vietnamese government for all the assistance rendered for the missing aircraft MH370," he said during a press briefing with his Vietnamese counterpart Nguyen Tan Dung.
Najib is on his first official visit to the country.
The two leaders also signed an agreement on agriculture and discussed trade, investment and issues in the South China Sea, where both countries have overlapping claims.
Malaysia is the 8th largest foreign investor in Vietnam. Bilateral trade reached 9 billion dollars last year, an increase of over 14 percent compared to the previous year.