They suggested you may send a guarantee letter to your agent company in USA.

他们建议由你们写一份保函到美国的代理公司。

youdao

Abstract:The ship industry develops slowly at present, and the risk of ship guarantee letter appears gradually.

摘要：船舶行业目前处于低谷，船舶保函业务风险日渐显现。

youdao

Provisional countervailing measures may be taken in the form of levying provisional countervailing duty under the guarantee of cash deposits or guarantee letter.

临时反补贴措施采取以现金保证金或者保函作为担保的征收临时反补贴税的形式。

youdao

For example, no one reading this letter can guarantee that they will be alive the next day.

ECONOMIST: When I'm 64

In recent days, students at Duke University, Apple CEO Tim Cook's alma mater, published an open letter calling on Cook and Apple to guarantee "conflict-free" products.

CNN: Apple, consumers must urge worker justice

Gennady Onishchenko, Russia's chief sanitary official, told Ekho Moskvy radio that he has sent a letter to the European Commission requesting a guarantee that meat products sold to Russia don't contain horse meat.

NPR: Russia Seeks EU Guarantees Over Horse Meat Scandal