Washington  - The United States will seek an immediate international meeting to broaden efforts against piracy off the coast of Somalia, US Secretary of State Hillary Rodham Clinton said Wednesday.

Clinton said that previous steps to counter piracy have not been enough, pointing to the recent surge of assaults on commercial shipping and hostage taking in the Indian Ocean, including last week's seizure of an American-flagged vessel.

"These pirates are criminals. They are armed gangs on the sea. And those plotting attacks must be stopped, and those who have carried them out must be brought to justice," Clinton said.

The United States has already helped established an international contact group on piracy that includes a coalition of navies to patrol the waters near Somalia. But the US military has said the area is too large to effectively patrol and the pirates have become more emboldened, expanding their reach hundreds of kilometres off the coast of Somalia.

The United States will send an envoy to a meeting in Brussels April 23 designed to help strengthen development, governance and policing in Somalia in order to prevent attacks, Clinton said.

US diplomats will engage Somali officials and regional leaders to explore ways to work together, and will also reach out to shipping companies to contemplate stronger security measures, Clinton said.

"Our envoy will work with other partners to help the Somalis assist us in cracking down on pirate bases and in decreasing incentives for young Somali men to engage in piracy," she said.

In the last year, more than 60 ships have been seized by pirates demanding a ransom in return for the cargo and crew. The trend gained heightened attention last week when pirates took control of the US- flagged Maersk Alabama. The American crew fought off the pirates, but not before the captain, Richard Phillips, was taken by the perpetrators onto a life boat.

After a standoff lasting several days, three US Navy SEAL snipers unleashed three shots from the nearby USS Bainbridge, killing the three pirates and rescuing Phillips. (dpa)