Reuters, WASHINGTON, Sep 20 : The US Senate voted twice today to keep shipments of Japan's Kobe beef out of the United States until Tokyo ends its ban on American beef, imposed 19 months ago as a precaution against mad cow disease.

Senators said the votes were a signal of frustration with Japan, traditionally the No. 1 customer for US beef exports.

The US cattle industry says it loses 100 million dollars each month the market is closed.

''It's just unfair,'' said Nebraska Democrat Ben Nelson, in decrying the continued ban as unjustified dawdling. ''It is time to move beyond soft talk to harder talk.'' A delicacy, Kobe beef comes from Wagyu cattle massaged with sake and fed a diet enriched with beer. Japan shipped $800,000 of the beef annually to US buyers before the ban.

Japan says the ban on American beef is in the hands of an independent food safety commission.

A subcommittee leader on the commission said last week that a draft report on American beef safety may be discussed soon but also cited difficulties in checking US plants. Cattle slaughtered at 25 facilities of four major meatpacking companies represent more than 80 per cent of all slaughtered animals, but the plants account for only 3.5 per cent of all US meatpacking facilities.

Prior to the ban, Japan imported beef from about 100 U.S. meatpacking plants.

On a 72-26 roll call vote, senators added language to a US Agriculture Department funding bill to bar USDA from issuing rules allowing imports of Kobe beef unless Japan fully opened its market to US beef. The USDA opposed the amendment as a possible obstacle to trade rather than a spur.

Senators also approved on a voice vote a nonbinding resolution, offered by Colorado Republican Wayne Allard, to keep out Japanese beef until US beef again was shipped to Japan.

Neither item was included in the House version of the $100 billion funding bill for USDA and related agencies. A final, compromise version of the bill must be written to iron out differences.

US cattle producers and their allies in Congress have stepped up complaints against Japan with the approach of the one-year anniversary on October 23 of a US-Japan agreement on a framework to resume trade. They say Japan now ample proof that US beef is safe.

''They're using mad cow disease as an excuse for an embargo against US beef,'' said Allard.

Always fatal, mad cow disease, formally called bovine spongiform encephalopathy, is believed to be caused by malformed proteins and spread through infected feed.

People can contract a human version of the disease by eating contaminated meats.