Outgoing U.S. ambassador to China, Gary Locke gestures as he speaks during a farewell press conference held at the U.S. Embassy in Beijing, China. Pic: AP.

BEIJING (AP) — The outgoing U.S. ambassador to Beijing urged China to respect the rights of peaceful political activists and said Washington is deeply concerned about the fate of a minority scholar charged with separatism.

Gary Locke made the call at his final news conference as ambassador on Thursday following a 2 ½ year tenure that included two serious diplomatic crises as well as a major expansion of trade and travel links.

Washington is “very concerned” about the case of Ilham Tohti as well as a recent increase in the arrests of social and legal activists and journalists, Locke said. Tohti is an economics professor and outspoken advocate for the Uighur Muslim minority who was arrested on Tuesday after being taken from his home one month ago.

China should value not just the economic welfare of its people, but also their freedom of speech, assembly and religion, Locke said.

“We believe that freedom of expression is a universal right and we very much are concerned about the arrest and detentions of people who are engaged in peaceful advocacy,” he told journalists at the U.S. Embassy in eastern Beijing.

“Human rights is more than just economic prosperity and economic conditions of people, but also fundamental universal rights of freedom of speech, freedom of assembly, the ability to practice one’s own religion,” Locke said.

State Department spokeswoman Jen Psaki on Wednesday also expressed deep concern over Tohti and called for his release.

China’s authoritarian communist government brooks no political opposition and routinely rejects such remarks. Beijing says it must take harsh measures against what it calls Islamic radical terrorists fighting for the independence of the northwestern China Uighur homeland of Xinjiang amid an uptick in violent incidents over the past year.

Asked about earlier comments on human rights by Locke, Foreign Ministry spokeswoman Hua Chunying on Wednesday said Beijing “strongly opposed anybody’s effort to use such issues to interfere in China’s internal politics and make irresponsible remarks.”

A former commerce secretary and two-term governor of Washington state, Locke, 63, was the first Chinese-American to serve as ambassador to Beijing. Known for his affable, non-confrontational style, Locke placed a high priority on improving embassy efficiency and facilitating bilateral trade at a time when exchanges are growing rapidly.

He also oversaw the defusing of two of the most delicate diplomatic episodes between the countries in years.

In February 2012, Wang Lijun, the police chief in the western city of Chongqing, fled to a U.S. consulate in southwest China with information about the murder of a British businessman, setting off China’s biggest political scandal in years. Wang’s flight led to the removal and subsequent sentencing to life imprisonment for corruption of Chongqing’s leader, Bo Xilai, formerly one of China’s most powerful politicians.

Just two months later, blind legal activist Chen Guangcheng escaped house arrest and was given shelter in the U.S. Embassy in Beijing, where he remained for six days before being allowed to leave the country with his family to study in New York.

Locke, a Democrat, said he had no plans for the immediate future but would stump for American political candidates and eventually return to China in a private capacity to work on business projects.

His replacement, former Montana senator Max Baucus, was sworn in last week and is expected to arrive within coming weeks.