Japan on Saturday refused to say when it would buy US beef again after Secretary of State Condoleezza Rice made a personal appeal for the former top market to resume imports stopped over mad cow disease fears.
Japanese Foreign Minister Nobutaka Machimura said after talks with Rice that Tokyo would make a decision on buying beef at an "appropriate" time.
"We fully realize this issue has deeply concerned the United States and Japan has been working to resolve this issue," he said.
"We are doing all we can to stop this issue from harming Japan-US ties," Machimura told a joint news conference.
US members of Congress from farm states have called for trade sanctions against Japan unless it resumes buying beef. But Japan says it is waiting for its health experts to approve a way to ensure the meat is safe, a process which could take months.
Rice, who also held talks with both Prime Minister Junichiro Koizumi, said in a speech earlier the beef ban was a dispute that clouded over otherwise strong ties between the allies.
"The time has come to solve this problem," Rice said at Sophia University in Tokyo.
"There is a global standard on the science involved and we must not let exceptionally put at risk our ability to invest and trade our way to even greater shared prosperity," she said.
Japan used to be the largest overseas market for US beef but Tokyo suspended the multi-billion-dollar trade in December 2003 after a cow slaughtered in Washington state was found to have mad cow disease, linked to a fatal brain condition in humans.
Japan has screened every cow slaughtered for consumption since September 2001 when it became the only Asian nation to report mad cow disease among its domestic herds.
After intense US pressure, Japan said in October it would exempt US cows aged 20 months or younger from screening tests if high-risk parts such as brains and spinal cords were removed.
The main dispute remains over how to verify the age of the cattle, with Japanese experts saying they did not have enough data to accept the method recommended by the United States.