(Corrects time of press conference in paragraph 2)

BEIJING, Aug 24 (Reuters) - China's foreign ministry said on Monday Beijing will closely watch developments and do what is necessary to protect its rights as the U.S. prepares to unveil new Iran sanctions that are expected to target Tehran's trading partners.

U.S. Treasury Secretary Scott Bessent, who is set to hold a press conference at 1 p.m. EDT (1700 GMT) on Monday, has threatened to impose "the toughest sanctions in history" on Iran and urged China to cooperate with Washington.

Speaking at a daily press conference on Monday, foreign ministry spokesperson Lin Jian also urged parties to act rationally with restraint, warning that sanctions and pressure tactics do not help to resolve issues.

(Reporting by Ethan Wang, Shi Bu and Colleen Howe; Editing by Thomas Derpinghaus)