President Bush added his voice yesterday to his administration's drumbeat of pressure on Western Europe in an attempt to break the stalemate over farm subsidies that has brought global free-trade talks to the brink of collapse.

In a White House meeting with the heads of the 12-nation European Community, Bush attacked what his chief trade adviser, Carla A. Hills, described as Europe's completely unacceptable negotiating stance on farm subsidies. He stressed the need for a successful finish to the stalled trade talks.

The meeting between Bush and his European guests -- Italian Prime Minister Giulio Andreotti, in his capacity as president of the EC, and Jacques Delors, president of the EC Commission -- had been called to try to forge a new relationship between the United States and the EC.

The hope was that the movement for a united Europe in 1992 would lead away from contentious trade issues in relations with the United States and toward broader political and security relationships.

"The timing was unfortunate," said an EC official, noting that the stalemate in the so-called Uruguay Round of trade talks brought yesterday's discussion right back to the trade issue.

"We discussed at length our goals for the Uruguay Round and our strong conviction that they must succeed. We pledged every effort to ensure the round concludes successfully in the coming weeks," Bush said during departure ceremonies outside the White House on a brisk fall evening.

Andreotti acknowledged in his farewell statement that the leaders had devoted a great part of their discussion to the problems with the negotiations on the General Agreement on Tariffs and Trade, known as GATT. He added that they all agreed that a failure of the trade talks would hurt the world economy, and especially the economies of the less developed nations.

But there was no hint of a solution to the farm trade issue, which has led more than a dozen farm exporting nations to threaten to bolt if there is no agreement to drastically reduce subsidies. Hills and Senate Finance Committee Chairman Lloyd Bentsen (D-Tex.) said in separate press conferences yesterday that the administration won't be able to win congressional ratification for a new GATT agreement that does not encompass lower EC farm subsidies.

The United States and other agriculture exporting countries contend that government payments to farmers in Europe undercut the ability of their own farmers to compete in international trade.

In the only sign of possible movement in the talks, Delors will continue his discussions here today.

It remained unclear what impact the president's discussion with Andreotti and Delors will have on the other leaders of the 12 nations that make up the European Community. While the Italians, along with Britain and the Netherlands, are more receptive to farm trade reforms, Germany and France have staunchly opposed cutting government subsidies, which have turned European farmers into major exporters on world markets.

Underscoring the sensitivity of the issue, thousands of European farmers marched on GATT headquarters in Geneva yesterday, blowing alpine horns and waving pitchforks to protest efforts to cut their subsidies, the Associated Press reported. They said farm trade liberalization threatens their livelihoods.

Earlier yesterday, Hills, prior to leaving for Europe to press the U.S. position, said the talks will collapse if the Europeans fail to produce a more forthcoming position on agricultural subsidies. Their present position, reached after six meetings, calls for a 30 percent cut in internal support payments, but it does not offer cuts in export subsidies or promise an end to trade barriers.

"I believe something should be accomplished this week," Hills said. "I will continue working ... but the fact that I will continue working does not mean that I will accept something less than fundamental reform in agriculture."

During her European swing, Hills will meet with German industrialists to try to persuade them that their ability to sell all over the world will be hurt if the trade talks fail over the agriculture issue.

Agriculture Secretary Clayton K. Yeutter is already in Europe pushing the U.S. position. They will be joined in Brussels this weekend by Secretary of State James A. Baker III for a ministerial-level U.S.-EC meeting, and Bush will have a chance to talk directly with other EC leaders next week during an all-European summit.