The proposal, which U.S. officials were weighing last week, involves a tariff-rate-quota system, according to a person familiar with the situation who asked not to be identified because the discussions are private.

Intensive talks are ongoing, according to European officials who declined to be identified.

Tariff-rate quotas allow countries to export specified quantities of a product to other nations at lower duty rates, but subjects shipments above a pre-determined threshold to a higher duty.

The parties have agreed to move forward on restoring historic trade flows and to have a system that’s compliant with World Trade Organization rules on trade, the spokesperson said. The U.S. Commerce Department and the Office of the U.S. Trade Representative didn’t immediately respond to requests for comment.

The parties will discuss the issue at the inaugural meeting of the U.S.-EU Trade and Technology Council on Sept. 29 in Pittsburgh, where State Secretary Antony Blinken, Commerce Secretary Gina Raimondo, and U.S. Trade Representative Katherine Tai will host European Commission Executive Vice Presidents Margrethe Vestager and Valdis Dombrovskis, another person said.