大虾们，帮忙看下是什么意思？

一个阿根廷客户我们产品，让我们银行担保，担保不到货就退钱给他们，总金额才USD20000，银行是不会随便给公司担保的。所以，我们就没答应银行担保，结果他今天又发来这封信 Please, we need you manage a Stand By Letter with your bank for the money that we are going to transfer. It is a regulation that imposes the World Bank. I hope you know understand. I will wait for your kind response. 不知道什么意思，请大虾们帮忙看下，谢谢了！