The cases were announced in the annual report by the US Trade Representative, Charlene Barshefsky, to Congress.

Charlene Barshefsky, the woman in charge of US trade policy

The seven complaints are over manufacturing, agriculture, intellectual property rights and government procurement.

Mrs Barshefsky said: "These actions underscore the administration's commitment to ensuring full compliance with existing WTO obligations."

She said that action against foreign government practices conflicting with existing international obligations would enable "the United States to open markets to US exports" and "identify US priorities for our future trade negotiations".

The seven cases are:

• Against the European Union in a dispute in which the United States is objecting to subsidies granted to France for a new flight management system adapted to Airbus aircraft.
• A second case against the EU in which the US is alleging unfair treatment for American farm products because of registration requirements.
• A charge that India is imposing unfair requirements on American automakers seeking to set up operations there.
• A complaint that South Korea is unfairly restricting the ability of American construction companies to bid on airport work.
• Another charge against South Korea that the country imposes unfair import restrictions against American beef.
• A case against Canada, saying it is unfairly restricting the length of time American products can receive patent protection.
• A complaint that Argentina is failing to provide proper patent protection for American products.

The report also said it would start an investigation into Canadian tourism practices, which allegedly hurts US hotel and other businesses on the border with its northern neighbour.

The actions are taken under US laws, identifying trade practices by other countries that allegedly harm US commerce.

In the past, the annual report was used to launch trade proceedings that often led to unilateral sanctions against Japan and other trade partners.

In recent years it has been used to identify cases the Washington government wants to bring before the WTO.