请将以下邮件翻译为英文

We currently have a shortage of staff and cannot take on this task. Judging from the present situation, the staff already have a saturated workload. I am handling the related business in Shanghai at the moment, and as you know this is very unreasonable and unusual. If we are to expand our business or change our scope, not only will we need sufficient time to step up the training for staff, but we will also have to make our difficulties known to management and let them decide whether to increase the number of staff or to handover the business. Therefore, at the moment I cannot promise you to handle the business in Beijing/Guangzhou next month.
Thank you for your understanding.