China criticized the U.S. for sending a group of former officials to Taiwan, saying the move will only add to mounting tensions.

Two former deputy secretaries of state, Richard Armitage and James Steinberg, and former Sen. Christopher Dodd were set to arrive in Taipei on Wednesday afternoon as part of a White House delegation marking the 42nd anniversary of the Taiwan Relations Act, the U.S. law governing Washington’s unofficial relationship with Taipei.

The American visitors will meet with President Tsai Ing-wen and senior national security officials during their three-day stay, according to the Taipei-based United Daily News.