The Peace Corps formally notified members of Congress this week that it will withdraw volunteers from China starting in June, according to a statement from Sen. Marco Rubio (R-Fla.)

The latest: In what could be another sign of worsening relations between China and the U.S. — amidst an 18-month trade war — the University of Maryland said on Friday that it will close its Confucius Institute, the earliest of its kind in America.

Background: The Peace Corps' retreat from China follows a December report from the bipartisan Congressional-Executive Commission on China (CECC) that determined there is a "strong argument" that China committed "crimes against humanity" in its northwestern region of Xinjiang.

What they're saying: "U.S. taxpayer dollars should not be used to bolster Communist China through the Peace Corps, and I’m glad they no longer will," Texas Rep. Michael McCaul, top Republican of the House Foreign Affairs Committee, said in a statement on Friday.

"Today’s decision by the Peace Corps to withdraw its volunteers from China confirms what we all know — China is no longer a developing country," Rubio said in his Thursday statement.

Go deeper: The stakes of a swift U.S.-China decoupling