US President George W Bush said Vietnam must increase political freedoms before "deeper" relations could exist between the two countries as Vietnam's president made a historic visit to the White House Friday, according to dpa. About 1,000 Vietnamese anti-communist protesters staged a noisy protest at the White House fence as the two leaders met, shouting "Freedom for Vietnam" and holding up placards. Vietnamese President Nguyen Minh Triet was the first head of state from the communist country to be received at the White House since the end of the Vietnam War in 1975, reflecting buoyant trade and improved political ties. The two leaders signed a new trade and investment agreement, a step toward a free trade pact, which both hailed as a sign of their strong economic relations. But Bush also urged Triet to improve the country's human rights record and increase political freedoms, after recent crackdowns on political dissidents and democratic activists reportedly placed Triet's White House reception in jeopardy. "I ... made it very clear that in order for relations to grow deeper, that it's important for our friends to have a strong commitment to human rights and freedom and democracy," Bush said. Triet said the two leaders had a "direct and open exchange of views" on human rights, but added that the countries' views remained "different" on the matter. "Our approach is that we would increase our dialogue in order to have a better understanding of each other," Triet said through a translator. "And we are also determined not to let those differences afflict our overall, larger interests." Triet's trip appeared to be in doubt in May after a six-month crackdown by Vietnamese authorities on political dissidents brought denunciations from Congress and the US State Department. Last week, Vietnamese authorities freed lawyer and democracy activist Le Quoc Quan, 36. He was taken into custody in March, days after returning from a US visit for human rights research. The US government expressed concern about his detention and the US House of Representatives passed a resolution demanding his release. Bush said he and Triet held a "frank and candid discussion" over a lunch of white tomato gazpacho, shrimp, crispy-skin filet of Black Sea bass and mango pudding, according to a menu released by the White House. It was the second time the two leaders met. Bush visited Hanoi in November - the second US president to make the trip since the Vietnam War - to attend a gathering of Asia-Pacific nations. US-Vietnamese relations have been on the upswing since former President Bill Clinton's controversial decision in 1995 to normalize relations and eventually visit Hanoi in November 2000, months before leaving office. The United States is Vietnam's largest export market, and trade between the two countries topped 9 billion dollars in 2006, a rapid climb from 1.5 billion dollars five years earlier. Triet met on Thursday with top lawmakers, including House Speaker Nancy Pelosi, who said the sides discussed trade relations and the US desire to see the emergence of democratic rule in the communist country.