A successful conclusion of talks between South Korea and the United States on a free-trade agreement would be a "wakeup call" to Japan and the U.S. for an accord between them, according to a former senior U.S. trade official.

"I think that would be a wakeup call to Japanese and American businessmen to say, 'Wait a minute, if the United States and Korea can do that, then maybe there are some things we can do as well, that will be beneficial to the two economies,' " Alan Wolff, managing partner of Dewey Ballantine LLP's Washington office, said in a recent interview.

The U.S. and South Korea launched FTA negotiations last week aimed at striking a deal by the end of the year.