我因受到时间及签证要求限制，可能不便参加会议以外活动，敬请谅解。

Sorry, I can only attend the meeting, but not the other activities, because I am restrained from the visa problem and limited time.

youdao

是这么回事，听起来能去参加会议就是个大好机会。你在大使馆申请签证了吗？

Well, being able to go to the conference sounds like such a great opportunity. Have you applied at the embassy for a visa yet?

youdao