U.S. President Barack Obama and Vietnamese President Truong Tan Sang pledged to finish talks on a regional free-trade agreement by the end of the year, but the two leaders clashed over human rights during a White House meeting. Labor and human rights groups have urged Obama to suspend free-trade negotiations with Vietnam because of that country's treatment of workers and people who criticize the government. The two leaders' meeting came as the 18th round of regional free-trade talks among the United States, Vietnam and nine other countries were wrapping up in Malaysia. Japan joined this week as the 12th country in the talks for the Trans-Pacific Partnership, known as the TPP. "We're committed to the ambitious goal of completing this agreement before the end of the year because we know that this can create jobs and increase investment across the region and in both our countries," Obama told reporters in the Oval Office. U.S. Trade Representative Michael Froman, who met with the Vietnamese leader on Wednesday, said he expected talks on the trade pact to intensify before the annual Asia Pacific Economic Cooperation summit in October, when all the TPP leaders will be together in Bali, Indonesia. Still, some doubt negotiators can finish the 3-year-old TPP talks by the end of the year. "They just brought in Japan three days ago. Is it possible to wrap up essentially a free trade agreement with Japan in five months? That's a big challenge," said Ed Gresser, a trade policy specialist at the GlobalWorks Foundation. 'Candid Conversation' Obama said he pressed his Vietnamese counterpart on human rights. "We emphasized how the United States continues to believe that all of us have to respect issues like freedom of expression, freedom of religion, freedom of assembly," he said. "And we had a very candid conversation about both the progress that Vietnam is making and the challenges that remain." Sang, in his translated remarks, said the two men still "have differences on the issue." The Worker Rights Consortium, a group of university administrators, students and other advocates that monitors working conditions in foreign countries, described in a recent report cases of forced labor and child labor, pregnancy and gender-based discrimination, health and safety hazards and excessive working hours and inadequate wages in Vietnam. The country has jailed an increasing number of dissidents, bloggers and religious leaders in recent years, holding them for long periods without access to family or legal counsel and often subject to torture or other mistreatment, according to Human Rights Watch. Obama said the two men also discussed issues from the war between the United States and Vietnam. Washington is still trying to recover missing fighters. Obama thanked Sang for cooperating in that effort and pledged to help Vietnam with lingering environmental and health issues resulting from the conflict that ended in 1975. (Reuters)