Following Apple's decision to stop paying licensing fees for smartphone chips, Qualcomm is reportedly planning to ask a U.S. trade agency to ban the imports of iPhones.

Bloomberg reports that Qualcomm is preparing to ask the International Trade Commission to stop the iPhone, which is built in Asia, from entering the country, threatening to block Apple's product from the American market in advance of its anticipated new model this fall.

The legal dispute revolves around patents Qualcomm holds related to virtually every modern high-speed smartphone, regardless of whether the devices use its chips. Apple argues the system is unfair and Qualcomm has used licensing leverage to illegally help its semiconductor unit.

Lats month, Apple cut off technology license payments to Qualcomm. As a result, Qualcomm is trying to intensify the fight to improve its negotiating position.

Spokesmen for Qualcomm and Apple declined to comment.

The iPhone is built in Asia by contract manufacturers. A successful appeal to the ITC could potentially lock it out of the U.S. market, which accounts for 40 percent of Apple's total sales.

The current iPhone uses modem chips made by Intel and Qualcomm. Up until the iPhone 7, Qualcomm was the exclusive supplier of that part.