China has been a partner with ASEAN and has been largest trading partner of the members of association. Seeking to match China's influence United States stepped in to increase economic relationship with ASEAN.

China and ASEAN signed the bilateral free trade agreement (FTA) in 2010 and has been the largest trading partner for six years consecutively. In 2014, the trade between China and ASEAN was reaching more than $480 billion, and China's direct investment in ASEAN countries reached $400 billion.

Seeking to match China's growing influence, U.S. seeks to expand its cooperation with ASEAN beyond its traditional leverage in political and security ties.

According to The Diplomat, U.S. State Department reported that ASEAN countries now are collectively America's fourth-largest trading partner. U.S. trade in goods with ASEAN countries has expanded by 55% to reach $226 billion in 2015. Foreign direct investment from United States in ASEAN has also increased to nearly doubled since 2008, with a total stock of over $226 billion.

Meanwhile China and ASEAN currently plan to increase cooperation. Reuters reported that on March 23, China offered $11.5 billion in loans and credit lines to five Southeast Asian countries for infrastructure and other projects. The announcement was made by Prime Minister Li Keqiang during summit with leaders from Myanmar, Laos, Thailand, Cambodia and Vietnam in Southern China.

Prime Minister Li said that he planned to push China's Asian Infrastructure Investment Bank and its Silk Road fund to finance the project. He also said to ensure greater use for Yuan to be used in dealing with the five countries which run along the same Mekong river. "There are six countries on one river. The Lancang-Mekong sub-region is our joint home," he said. "Over the many years of being neighbours we have become family."

The inaugural meeting was held in the resort town of Sanya on Hainan island to introduce Lancang-Mekong Cooperation. The name was derived from the river that begins in Tibet and discharges into the South China Sea in southern Vietnam. China Prime Minister and Thai Prime Minister Prayut Chan-ocha co-hosted the meeting which aimed to strengthen ties and cut trade deals in the region.

New York Times reported that escalating territorial conflicts have complicated China's effort to court its Southeast Asian neighbors and partners. Beijing also concern with the signed that ASEAN may draw closer to its rival United States.

Traditionally, China and ASEAN have closer economic ties than United States, as U.S. only holds political and security advantage in ASEAN. 

U.S. tries to balance the China's influence in Southeast Asia. As fears of increasing economic reliance from ASEAN countries on China may affect U.S. interest in Southeast Asia. Therefore, U.S. seeks to balance China by trying to increase economic partnership with ASEAN.