### Chinese: 伊核协议相关方今年4月开始在奥地利首都维也纳举行会谈，讨论美伊两国恢复履约问题。
### English: Relevant parties in the Iranian nuclear deal began to hold talks in Vienna, Austria, in April this year to discuss the resumption of compliance between the United States and Iran.
### Errors: There is a minor error at "p". There is a minor error at "compliance".

### Improved English: Related parties of the Iran nuclear agreement started hosting talks in Vienna, the capital of Austria, since this April, to discuss the problem of restoring honoring the agreement by the US and Iran.