A letter to the Eve auction house on Friday from Jane Hartley, the US ambassador to France, called for the objects to be pulled from bidding while the Hopi and Navajo tribes "determine if they have recourse to seek their return".
A Navajo delegation argues the objects belong to the tribe — which considers them living beings — after viewing the items at the Drouot auction house in Paris, according to an embassy statement.
The delegation spotted eight "sacred" masks and a series of Hopi statuettes and representations of faces.
In addition to taking the items off the auction block, Hartley has asked Eve director Alain Leroy to encourage a dialogue between the sellers and the tribes that would lead to the objects' return to the Navajo and Hopi.
Meanwhile, the Hopi tribe and the native peoples defence group Survival International asked a court on Friday to order the release of the sellers' identities.
Activists' previous attempts to block auctions of Native American objects in France have failed, with French courts rejecting three prior requests from the Hopi and Survival International since April 2013.
Previous pressure from the United States on Eve to halt sales of objects from the tribes were unsuccessful as well.
An auction of Native American masks originating from the Hopi tribe went ahead in June despite objections from the US embassy and members of the 18,000-strong community located in the US state of Arizona.
However, supporters of the tribes have found a costly, but effective way to get the items back: buy them.
The Annenberg Foundation purchased 21 Hopi masks and three San Carlos Apache objects at auction in 2013 for $530,000 (€390,000) "for the sole purpose of returning them to their rightful owner," it said