HANOI Vietnam's Prime Pham Minh Chinh has visited the headquarters of Nvidia and Synopsys, encouraging them and other U.S. tech firms to invest further in the Southeast Asian country's semiconductor industry.

"Vietnam is willing to open its doors to all investors to invest and do business there," a government statement quoted Chinh as telling a technology business forum in San Francisco during his visit to the United States.

Chinh's trip comes on the heels of a visit by U.S. President Joe Biden to Hanoi this month during which the two leaders announced improved bilateral relations and plans to deepen cooperation in several areas, including chips, AI and critical minerals.

Chinh pledged to facilitate future investments by Nvidia and Synopsys in Vietnam, the statement said.

The statement quoted Nvidia CEO Jensen Huang as telling Chinh that "Nvidia wants to cooperate with Vietnam in semiconductor, information technology and artificial intelligence."

Synopsys, which has plans to build chip design centres in Vietnam, on Monday signed memorandums of understanding with Vietnam's information ministry and with the investment ministry.

Nvidia, a top supplier of servers to Vietnam, and Synopsys did not immediately respond to Reuters requests for comment.

U.S. chipmaker Intel has its biggest factory for assembling, packaging and testing chips in southern Vietnam, while rival Amkor is building a large factory for semiconductor assembly and testing near Hanoi.

Chinh is in the U.S. for the United Nations General Assembly this week, after which he plans to visit Brazil.

(Reporting by Khanh Vu; Editing by Edwina Gibbs)