"The two sides agreed to cooperate in seeking a mutually satisfactory solution ... and noted that more time was needed to come up with practical steps," South Korea's trade ministry said in a statement.
It said it would continue to talk with Washington to allow in beef only from cattle younger than 30 months old.
Seoul agreed in April to open up the local market for all cuts of U.S. beef from cattle of any age, which could have led to the first full resumption of imports of the U.S. product in more than four years.
It imposed a blanket ban on U.S. beef in late 2003 following a U.S. mad cow disease outbreak.
Since the agreement South Korea delayed resumption of quarantine inspections on U.S. beef twice due to public concerns over the safety of U.S. meat, and said it would not resume imports until a new deal with Washington was reached that allowed in beef only from cattle younger than 30 months, which are deemed less susceptible to mad cow disease.
"Frank and candid discussions were held... Korean Trade Minister Kim (Jong-Hoon) is returning to Korea, but our officials continue to remain in contact," Gretchen Hamel, a spokeswoman for the U.S. Trade Representative, said in an emailed statement.
U.S. trade officials and the beef industry disclosed little about their goals for the Washington meeting, though the Bush administration had said it was looking for "a mutually agreeable path forward."
South Korea, which is hoping to cast its bid to cool unrest at home as a retooling, rather than renegotiation, of the beef agreement, sees a voluntary agreement in which U.S. exporters restrict shipments to younger cattle as one solution.
South Korean President Lee Myung-bak, who took office just three months ago, sparked widespread public anger with his decision to allow U.S. beef back into the country.
Lee is expected to replace several ministers in a bid to ease the unrest, which has paralyzed his government's reform agenda and sent his popularity plummeting.
The U.S. meat industry is keen to get the green light to ship a full range of products to the lucrative South Korean market, which was the third-largest buyer of U.S. beef before Seoul clamped down on imports.
The resumption of the beef trade is also important to supporters of a still-unapproved bilateral free trade deal, which U.S. lawmakers have promised will not advance until the beef question is settled.