WASHINGTON, May 12 (Xinhua) -- The U.S. Coast Guard urged on Tuesday U.S.-flagged ships sailing around the Horn of Africa to hire armed or unarmed guards.

    The Coast Guard's director of prevention policy, Rear Admiral James Watson, said at a maritime security meeting in Florida that new measures should be taken to respond to the increasing pirate attacks off the Somali coast.

    "We expect to see additional security on U.S.-flagged vessels that transit these waters," said Watson.

    He also said that owners of all U.S.-flagged ships have to submit anti-piracy security plans by May 26, and "tell us what they propose" for approval.

    The piracy issue came under spotlight after a U.S.- flagged Danish cargo ship was attacked last month off the Somali coast, leading to a several-day standoff between U.S. military and pirates.

    The U.S. government and military have since called for a new strategy to protect the U.S.-flagged boats from being attacked by pirates, including hiring armed guards on board.

    However, shipping industry is hesitating to take the advice since some countries will not allow armed vessels to enter their ports, and the measure is considered likely to increase risks of violence.

    Watson said that the State Department was working with countries in pirate-plagued regions to learn what weapons laws apply in their ports in order to clarify the issue for U.S. shipping industry.