U.S. Secretary of State Hillary Clinton called for closer ties between Washington and its former wartime foe Vietnam, even as she said the government in Hanoi isn’t doing enough to respect human rights.

Reuters Mrs. Clinton with Foreign Minister Pham Binh Minh in Hanoi on Tuesday.Speaking in the Vietnamese capital on Tuesday in the midst of a cross-Asia  tour, Mrs. Clinton touted the widening commercial links between the two nations, with trade reaching $22 billion in 2011, from $1 billion in 2001. The two countries have also moved closer in recent years as Vietnam seeks more support in its long-running disputes with China. Beijing’s extensive territorial claims in the resource-rich South China Sea overlap with those of Vietnam and other Southeast Asian nations, leading to growing fears of a regional conflict.

Mrs. Clinton said she hoped Asian leaders would work together to come up with a solution to the territorial disputes. She encouraged the development of a fresh code of conduct for activities in the sea at an Association of Southeast Asian Nations summit this week in Cambodia, to ensure future disagreements are resolved amicably.

"The U.S. greatly appreciates Vietnam’s contribution to a collaborative, diplomatic resolution of disputes and the reduction of tensions in the South China Sea,” Mrs. Clinton said at a briefing after meetings with Vietnamese Foreign Minister Pham Binh Minh.

But Mrs. Clinton said she remains concerned that Vietnam’s government isn’t doing enough to protect the rights of its citizens, including protections for free expression online. Vietnam has at times instructed Internet-service providers to block access to sites such as Facebook and Twitter in recent years, while police have detained some well-known bloggers. Human-rights groups say such actions are designed to limit dissent.

"I know there are some who argue that developing economies need to put economic growth first and worry about political reform and democracy later, but that is a short-sighted bargain,” Mrs. Clinton said. "So I also raised concerns about human rights, including the continued detentions of activists, lawyers, and bloggers, for the peaceful expression of opinions and ideas.”

Mr. Minh said at the briefing he was hopeful that relations between the countries would continue to warm, however, especially through economic links.

U.S. officials are keen to keep promoting commercial ties between the two countries, to create new opportunities for American companies abroad and to help shore up relations with Hanoi as Washington seeks to contain China’s influence in the region.

Although Vietnam has been a major destination for U.S. investment in recent years, it has become somewhat less attractive more recently because of macroeconomic instability, marked by high rates of inflation and a series of currency devaluations. Analysts have argued Vietnam needs to pursue more economic overhauls, including steps to privatize state companies, to give its economy a new boost.

At an American Chamber of Commerce event in Hanoi Tuesday, Mrs. Clinton said she was encouraging Vietnamese officials to keep reforming the economy, especially by opening markets further to private investment. She said the U.S. was also doing its part by joining with local companies and nongovernmental organizations to boost skills training and build a better-educated workforce—long a concern for major multinational companies operating in Vietnam such as Intel Corp..