The World Trade Organization's highest court ruled on Monday that U.S. steel import duties violate trade rules, putting pressure on Washington to remove them. The European Union has warned U.S. President George W. Bush to remove the 20-month-old tariffs, put in place to protect the ailing American steel industry, or face retaliation, which could include $2.2 billion in duties on U.S. goods. The EU, along with a group of countries including Japan, Brazil, South Korea and Switzerland, had filed a complaint with the Geneva-based WTO complaining that the steel duties were a barrier to free trade. The United States had argued that the duties, which were initially for up to 30 percent but which were later lowered, were necessary to protect U.S. steel makers from a flood of cheap imports, but a panel of WTO judges disagreed. The 22 countries that filed complaints hailed the decision. "It leaves the United States with no other choice but to terminate its WTO incompatible safeguard measures without delay," they said in a joint statement.