South Korea is sending its chief trade official to Washington for what he describes as "additional" negotiations on a controversial beef import deal. However, leaders of mass protests say nothing short of scrapping the deal and restarting negotiations will be acceptable. VOA's Kurt Achin reports from Seoul.

South Korean Trade Minister Kim Jong-hoon told reporters in Seoul he will leave Friday for Washington, where he plans to ask for help in adjusting the explosive April deal to resume American beef imports.

He calls the planned talks "additional negotiations." He will look for ways to limit American beef imports to meat from cattle under 30 months of age, as a way to end massive protest rallies.

South Korean protesters fear U.S. beef - especially from cattle more than two-and-a-half years old -- poses a risk of transmitting a fatal brain ailment known as "mad cow disease." Tens of thousands of people have gathered in central Seoul, almost nightly for about a month - culminating in Tuesday's massive rally that appeared to include about 100,000 people.

Washington has asserted American beef, of any age, is safe. That view was supported last year by the United Nations World Organization for Animal Health. No human has ever been known to contract brain disease from eating U.S. beef. South Korea's scientific community has been conspicuously absent from the highly politicized protest movement.

American lawmakers have warned the resumption of U.S. beef imports to South Korea is a prerequisite for ratifying a much larger trade deal the two countries signed last year. Minister Kim, who was South Korea's chief negotiator in the deal, says he does not want to create the appearance his country is breaking its promises.

He says the wise course of action would have the same effect as a renegotiation, without damaging South Korea's international credibility.

He says his mission is to seek a "voluntary" agreement between importers and exporters that would keep older beef from being shipped.

Analysts say such an agreement could be backed by government assurances and spelled out in the form of some new document to be signed by both countries. U.S. Ambassador to South Korea Alexander Vershbow said Thursday "additional understandings" are likely to emerge between the two countries "in a matter of days."

That may not be enough to satisfy protesters, for whom the beef issue has become a touchstone for a host of grievances against South Korean President Lee Myung Bak. Protest leaders have vowed to continue holding the mass gatherings until at least next week.