a US official的用法和样例：
- Russia and China called on Pyongyang to return to talks, while a US official urged it not to aggravate tensions.
- McCain off the coast of the Philippines, according to CNN, quoting a US official who said it was an "inadvertent encounter".
- The size and scope of the exercise ensured that the US and other nations in the region saw it, said a US official, who estimated the distance was about the same as from Israel to Natanz.
- A sauna in the hotel would be a useful amenity.
- It was a put-up job on the part of us officials.
- Please send us official receipt.