The U.S. military dispatched two B-52H bombers from the United States to the Middle East on Thursday as part of an ongoing effort to deter Iran from potential attacks amid increased risk in the region, according to a senior U.S. military official.

The United States is ready to impose sanctions on Turkey over its purchase of Russian S-400 air defense systems last year, four sources including two US officials told Reuters on Thursday.

China’s Foreign Ministry said Thursday it is restricting travel by some U.S. officials to Hong Kong after the U.S. placed financial sanctions and a travel ban on 14 Chinese officials.