(Bloomberg) -- Vietnam’s Communist Party General Secretary Nguyen Phu Trong and US President Joe Biden discussed strengthening bilateral ties across the board during a phone call on Wednesday.

Trong suggested both sides continue expanding economic cooperation, work to ensure supply chains and realize agreements on national defense and security cooperation, according to a Vietnamese government readout. Both sides further accepted reciprocal invitations for mutual high-level visits to be worked out by relevant agencies.

“He stressed the need for both sides to increase contacts and exchanges between the two sides’ agencies at all level in a flexible manner, including enhancing relations between Governments, parliaments, parties and peoples to strengthen the two countries’ ties more sustainably and substantively,” according to the readout. The general secretary is considered the Communist Party’s most powerful position in Vietnam’s one-party state.

The Biden administration is seeking to bolster its status as an indispensable security partner to Southeast Asian countries amid growing concerns over Chinese incursions in the South China Sea, a key transit area for trade and a major source of oil and gas. In the latest episode over the weekend, a Vietnamese ship was sent to monitor a Chinese Coast Guard vessel in a Russian-operated gas field, Reuters reported citing data. 

At the same time, Vietnam has sought to maintain good relations with China as a major source of foreign investment. The party chief paid a visit to the country shortly after the conclusion of the 20th National Congress of the Chinese Communist Party last year and both sides pledged to further deepen their comprehensive strategic cooperative partnership.

Vietnam, like most Southeast Asian nations, has maintained neutrality over growing tensions between the US and China, and Trong stressed a foreign policy of independence and “self-reliance” during his call with Biden. For his part, Biden identified trade, clean energy and energy transition as potential areas of cooperation between the two countries.

--With assistance from Nguyen Dieu Tu Uyen, Mai Ngoc Chau and Karthikeyan Sundaram.

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