WASHINGTON (Reuters) - On the eve of the expected signing of the first phase of a trade deal between the United states and China, a bipartisan group of U.S. lawmakers has called on President Donald Trump to press Beijing to free detained Americans and U.S. residents.

A House staff member adjusts an American Flag ahead of a news conference at the U.S. Capitol in Washington, U.S., January 14, 2020. REUTERS/Tom Brenner

The legislators - six senators and House representatives - expressed “deep concern” about China’s imprisonment or arbitrary detention of U.S. citizens and permanent residents and the imposition of exit bans on Americans.

“We request that you meet with the families of Americans whose loved ones are being held in China and that you persistently raise the... cases in discussions with Chairman Xi Jinping and other senior Chinese officials,” they said in a letter to Trump made public on Tuesday.

It listed seven detained U.S. citizens or permanent residents, including two pastors, a businessman and two Americans who ran an English-language teaching company.

The letter said the Chinese government used exit bans as a tool “that disproportionately targets American citizens of Chinese descent.”

The lawmakers also called on Trump to seek the release of relatives of American citizens and permanent residents detained in the Xinjiang Uighur Autonomous Region, where the Chinese government is accused of mass persecution of Muslims.

“These family members... need the administration to be tenacious advocates for them and the estimated 1.8 million ethnic Uighurs and other Turkic Muslims arbitrarily detained in the XUAR,” the letter said.

The lawmakers who signed the letter were led by Republican Marco Rubio and Democratic Representative Jim McGovern, co-chairs of the Congressional Executive Commission on China.

The Chinese Embassy did not immediately respond to a request for comment.

Signing of the first part of the trade deal on Wednesday should ease Trump’s 18-month trade war with China, but will do nothing to reduce a growing strategic rivalry, amid which U.S. officials have increasingly taken aim at China’s human rights record.

China said in October that two U.S. citizens mentioned in the letter - Alyssa Petersen and Jacob Harlan, who worked for U.S.-based education company China Horizons - had been released on bail and were awaiting trial on charges of illegally moving people across country borders.

The congressional letter also named John Cao, a pastor and a U.S. legal permanent resident it said was sentenced to seven years in prison, also for allegedly organizing “illegal border crossings,” and Kai Li, a U.S. citizen arrested on state security charges and sentenced to 10 years in prison in 2018.

The letter also listed David Lin, an American pastor detained in 2006 and convicted on fraud-related charges, who is not scheduled for release until 2030, and Victor and Cynthia Liu, whom it said had been prevented from leaving China since 2018.

The letter said their mother, Sandra Han, was detained on criminal charges in China and the family’s New York-based attorney believed they were being used as human collateral to coerce their father, Liu Changming, to return to China to face fraud charges.