HANOI: Vietnamese Communist Party chief Nguyen Phu Trong doesn't hold an official government post, but it's not surprising that he'll meet with President Barack Obama on his visit to the United States this week. He is the de-facto top leader of his country. More telling is one of Trong's other engagements — a dinner reception hosted by the US Chamber of Commerce, bastion of American free enterprise. Economic imperatives drove the US and Vietnam to normalize postwar relations 20 years ago, and they remain a major incentive to boost ties. President Bill Clinton announced the normalization of relations between the US and Vietnam on July 11, 1995, following up on the lifting of punitive economic sanctions imposed after the Vietnam War ended in 1975 with a communist victory. The bitterness on both sides gave way to pragmatism. Vietnam's socialist planners were running the economy of the newly unified nation into the ground, and needed a helping hand. American businesses saw opportunities that might otherwise be seized by Asian and European competitors. Trong called his trip on Tuesday 'a historic visit.' He said he expects Obama to make his first visit to Vietnam later this year, though the White House has not confirmed the trip. US officials are eager to take relations with Vietnam — currently friendly but hardly intimate — to a new level. Vietnam could be a linchpin in Obama's 'pivot' toward Asia, playing a strong geopolitical and economic role. As a front-line country nervous about Chinese expansionism in the South China Sea, Vietnam also would not mind the US directing at least a little hard talk at Beijing. 'We believe that as one of the world's leading major powers and a member of the (U.N. Security Council), the US has a great interest and responsibility in maintaining peace and stability in the world, particularly in the Asia-Pacific,' Trong said Friday in a written response to questions submitted by The Associated Press. In careful diplomatic language, he said he hoped 'that the US will continue to have appropriate voice and actions to contribute to peaceful settlement of disputes in the (South China Sea) in accordance with international law in order to ensure peace and stability in the Asia-Pacific and the world.' US ambitions to remain a Pacific power hinge in large part on projecting its power by drawing a line with China. Popular sentiment in Vietnam is generally hostile toward China's assertive maritime territorial claims, but the country's leaders are loath to antagonize their much bigger neighbor. The practical perils of proximity are one matter, but more doctrinaire communists such as Trong are uneasy about casting their lot with the democratic West instead of their old communist kin in Beijing. In Washington's view, however, wooing a hard-line skeptic such as the 71-year-old Trong is key to achieving the two countries' goals. While Trong's trip is a sign of how far the US-Vietnam relationship has come in the 40 years since the end of the war, that doesn't mean an alliance is in the works, said Walter Lohman, director of the Asian Studies Center at the Heritage Foundation in Washington. 'They want to have eggs in the American basket to balance off what they've got in the Chinese basket, all in the service of Vietnam's interest and strategic vision,' he said. Trong emphasized the importance of Vietnam's relationship with the US. 'Vietnam would like to be a friend and reliable partner of all countries in the world,' he wrote in his response. 'In this effort, we attach great importance to the relations with the US as one of the most important partners in our foreign policy.' What Washington has to offer Hanoi are economic benefits, particularly under the yet-to-be finalized multilateral Trans-Pacific Partnership. It can point to a solid track record: Since 1995, annual U.S.-Vietnam trade has increased from less than $500 million to $35 billion last year. Vietnam has now surpassed Malaysia and Thailand as Southeast Asia's top exporter of merchandise to the US . Trong's visit 'is part of the discussion in Hanoi about the nation's future ... how to balance the economic and political links with China against the lure of US markets and security assurances,' said Frank Jannuzi, a former Senate Foreign Relations Committee staffer who now works at the Washington-based Mansfield Foundation, which aims to promote US-Asia relations. Jannuzi pondered whether the trade pact's economic benefits and US guarantees on South China Sea security would carry the day, or if Vietnam's communist government would stick to the model of their Chinese comrades 'and follow the path of resilient authoritarianism, with state control of key sectors of economy and strict controls on power-sharing.' Human rights remains a sticky issue, with Vietnam's repression of dissidents undercutting political support in the US Congress for sweetening any deals with Vietnam, such as acceding to Hanoi's desire to be allowed to purchase lethal weaponry. The Obama administration 'deserves credit for continuing to pressure Vietnam on political prisoners, labor rights and religious liberty. The problem is, it's not working,' said John Sifton, Human Rights Watch's Asia advocacy director in Washington. The US says prosecution of dissidents has decreased and the number of political prisoners has dropped from more than 160 two years ago to around 110 — progress it attributes to Hanoi's desire to join a US-backed trade pact of Pacific Rim nations. But Sifton said the reduction was due to people serving out their terms, not early releases. Human Rights Watch estimates there are still about 150 political prisoners being held. Trong acknowledged differences with the US on issues of democracy, human rights and trade. But he added: 'We should maintain dialogues in an open, candid and constructive manner to increase mutual understanding, narrow differences and make best use of our cooperation potentials. We should work to make sure such differences do not hinder bilateral relations.'