A military-backed government in 2006 suspended patent protections for expensive cutting-edge treatments for AIDS, cancer and heart disease, giving Thais access to cheap copycat versions.
Activists against AIDS and poverty hailed Thailand as a global leader, but the kingdom has faced heavy pressure and threats of legal action from Western pharmaceutical firms.
Trade Representative Kiat Sittheeamorn told the American Chamber of Commerce in Thailand that the government was in talks with all sides and hoped for an eventual solution under the World Trade Organization.
"What we would like to see is US engagement with the WTO in order to come up with a multilateral regime that is good for all," Kiat said in remarks videocast in Washington.
"It is a very sensitive issue, but we also recognize that we don't want to violate any patent rights," he said.
"I think the final goal for all is to be able to have affordable drugs for all the Thai people while recognizing the ownership rights" of patent holders, he said.
Campaigners voiced outrage last year when they said they obtained a letter showing Prime Minister Abhisit Vejjajiva's government would not license more generic drugs as the issue was holding up free trade talks with the United States.
In its last annual report in March 2009, the US Trade Representative's office said Thailand was within its WTO rights to approve generic drugs but called for "transparency and due process."
Major pharmaceutical firms argue that generic drugs ultimately hurt patients by depriving the companies of funding for research and development.
Former US president Bill Clinton in 2007 struck a deal with two generic drug makers in India that now provides lower-cost AIDS treatment to more than two million people in developing countries, including Thailand.