PARIS, AUG. 21 -- Nine European nations vowed today to expand their naval operations in the Middle East to share responsibility with the United States for enforcing United Nations sanctions against Iraq.

The foreign and defense ministers of the nine-nation Western European Union (WEU), which has become the principal forum for European allies to coordinate defense and security policies outside NATO, also backed U.S. calls to employ force if necessary to prevent commercial vessels from breaking a global ban on trade with Iraq, which invaded Kuwait Aug. 2.

Later, foreign ministers from all 12 European Community states denounced the detention of Westerners in Iraq and Kuwait and insisted their countries will defy Baghdad's orders to close down embassies in Kuwait by the end of this week. France's Roland Dumas said the "inhuman treatment" faced by the hostages "revolts all of us," and he warned Iraq that there would be "grave consequences" if any were harmed.

In London, British Prime Minister Margaret Thatcher broke a two-week public silence to denounce Iraq's seizure of Britons. Thatcher echoed President Bush's earlier acknowledgment that the 7,500 British and American citizens being held in Kuwait and Iraq are indeed "hostages" and said Britain would never succumb to "blackmail" and negotiate with Iraq for their release. She called the seizures "utterly repulsive" and said: "No civilized country behaves in this way."

Thatcher also had some harsh words for the International Committee of the Red Cross, accusing it of inexplicable delays in responding to a British request that it help foreign nationals in Iraq and Kuwait. "We are deeply disappointed that action has not yet been taken," she said.

Red Cross officials have said that Iraq refused their requests to enter Kuwait. "Without the agreement of the Iraqi government, the ICRC is limited in what it can do," American Red Cross Executive Vice President Stephen H. Richards said today in Washington.

Anger over the plight of the roughly 13,000 Westerners still trapped in Iraq and Kuwait has started to galvanize a tougher response by European governments toward Iraqi President Saddam Hussein's regime. Sentiment among many allies has begun to mirror the Bush administration's rejection of Iraqi demands that Western troops be withdrawn from the region before the Westerners will be released.

Four WEU members -- the Netherlands, Belgium, Italy and Spain -- and Greece, an EC member, announced they were sending warships to the Middle East to join French and British air and naval units already deployed in the region.

West Germany, which has not sent forces to the gulf because of constitutional restrictions, will send vessels to patrol the eastern Mediterranean, filling in for other allied ships sent to the gulf region. Bonn will seek to change its constitution in coming months to permit the deployment of its forces beyond Europe, according to Foreign Minister Hans-Dietrich Genscher.

Senior military officials from the nine WEU countries will meet Friday to work out "the sharing of tasks, logistical support and exchange of intelligence" among their forces, according to a joint declaration issued after the meeting.

French President Francois Mitterrand, speaking at a press conference in Paris after chairing a high-level government meeting on the Persian Gulf crisis, said ground reconnaisance forces would be part of a troop contingent the Paris government plans to send to the Arabian Peninsula. An army intelligence unit would be sent to the United Arab Emirates, and additional military instructors would be flown to Saudi Arabia in response to requests from those countries for security assistance, Mitterrand said.

Mitterrand declared, "We are at this time . . . in a war mindset" because of Saddam's refusal to allow the trapped foreigners, including 560 French citizens, to leave.

After resisting American calls for a blockade of Iraqi trade, France gave orders Sunday to its 3,000-man naval force in the gulf region to use force if necessary to ensure compliance with the United Nations sanctions. This came after it was learned that at least 27 French nationals had been transferred to strategic locations in Iraq to serve as a shield against possible Western attack.

In Vienna, opposition parties today claimed the Austrian government's decision to let U.S. military aircraft fly over the Central European nation en route to the Middle East violated its neutrality laws. Foreign Minister Alois Mock defended the move, made 10 days ago, calling it an act of solidarity with Kuwait and repeating Washington's assurances that the planes carried no heavy weapons.

About 60 Austrians living in Kuwait began driving across Iraq today bound for Turkey, according to the Austrian Foreign Ministry. Iraq has said Austrian nationals will be allowed to leave Iraq and Kuwait.

The WEU ministers in Paris stressed that the concerted approach taken by their countries should not interfere or conflict with the U.S.-led multinational force based in Saudi Arabia. They contended that more cohesion among the smaller, disparate European contingents would make the multinational operation easier to manage.

Today's meeting produced the first joint European military initiatives in the gulf by the European allies since the Iraqi invasion of Kuwait nearly three weeks ago. WEU Secretary General Willem van Eekelen said, "We in Western Europe see the need to act so that the United States is not left to have to do the job alone."

While recognizing that the gulf crisis has become a test of Europe's stated goal of doing more for its security interests, Genscher and other ministers emphasized that any European action should be couched in terms of working with Arab countries, not just the United States, to uphold international law.Correspondent Glenn Frankel in London and special correspondent Michael Z. Wise in Vienna contributed to this report.