The United States Postal Service isn't on the same page with a major Chinese company that claims they have an agreement in the works.

The USPS would not confirm or deny to CNBC the existence of an agreement with a major Chinese package-shipping firm that just launched an initial public offering in the United States. Meanwhile, the Chinese company in question has posted photographs online of an apparent deal signing between the two.

Shanghai-based ZTO Express debuted on Oct. 27 as the largest U.S. IPO of the year, and chief financial officer James Guo told CNBC then that the company had recently entered a partnership with the United States Postal Service for handling cross-border transactions.