Fifteen senators led by Ron Wyden, an Oregon Democrat, and Lamar Alexander, a Tennessee Republican, sent a letter to U.S. Trade Representative Michael Froman urging passage of the Trans-Pacific Partnership free-trade accord to end tariffs on footwear imports.

A similar letter was sent by 47 House members, according to a report in Bloomberg News. That letter was led by Representatives Earl Blumenauer, an Oregon Democrat, and Aaron Schock, an Illinois Republican.

The 11 TPP nations, which will include Japan by the end of the month, are seeking to create an economic zone with $26 trillion in annual output. Other nations forging the Pacific accord are Australia, Brunei, Canada, Chile, Malaysia, Mexico, New Zealand, Peru and Singapore. Negotiators are seeking to reach an agreement by the end of the year.