WASHINGTON — The U.S. will delay — by at least two weeks — imposing additional duties on a modified list of E.U. products, due to recent positive developments in the ongoing negotiations with the E.U., announced U.S. Trade Representative Ron Kirk. 

The duties are being considered because of an ongoing dispute with the E.U. over hormones used in U.S. beef. The additional duties were to go into effect on April 23, relays The American Meat Institute.

 "The EU. has demonstrated seriousness in their efforts to solve this problem, and two additional weeks should be sufficient to establish whether we can address the remaining issues successfully," Mr. Kirk said. 

Talks will begin in earnest on April 27, in Geneva. E.U. Trade Commissioner Catherine Ashton spoke to Kirk on April 21 and April 22 in an effort to put an end to the row, with Ms. Ashton giving a personal commitment to resolve the dispute.

 "It appears as if progress is being made and we urge the two sides to resolve this issue as soon as possible," said J. Patrick Boyle, A.M.I. president and chief executive officer.  "We hope that this dispute can be resolved and allow the U.S. greater access to the European Union market."

U.S. negotiators will fly to Geneva this weekend.

The beef-hormones dispute has been a thorny issue between the U.S. and E.U. It dates back to the late 1980s, when the E.U. banned beef from cattle raised with artificial growth hormones, a common industry practice in the United States and Canada. In 1998, the W.T.O. found that the E.U.’s ban on U.S. beef was not supported by science and was thus inconsistent with W.T.O. rules. 

When the E.U. failed to bring its ban into compliance with its W.T.O. obligations, the W.T.O. authorized the United States to take retaliatory trade measures with an annual trade value of $116.8 million, A.M.I. pointed out.  In July 1999, the United States imposed additional duties on a list of E.U. products in accordance with the W.T.O. authorization. That list remained unchanged until the modifications were announced on Jan. 15, 2009.