Pressure for action has intensified since the seizure of a Ukrainian ship
The Nato military alliance says it will send warships to help combat piracy off the coast of Somalia.
Nato defence ministers meeting in Hungary agreed to despatch a joint task force by the end of the year.
The force will also escort UN ships delivering aid to Somalia, where more than 3m people - almost half of the population - are in need of food aid.
Pressure for action against the pirates has intensified since a ship carrying 33 tanks was seized last month.
Warships from several countries are already patrolling the waters because of the rise in piracy attacks.
Piracy is a lucrative business with huge ransoms demanded
Meanwhile, a Japanese chemical tanker seized in August in the Gulf of Aden has been freed.
There are reports that a $1.6m (£931,000) ransom was paid.
The UN this week passed a second resolution authorising the use of force against pirates.
Somalia has been without a functioning central government for 17 years and has suffered continual civil strife, with rival armed clans and groups fighting for control.
Nato spokesman James Appathurai said the ships would be drawn for a standing maritime group of seven vessels which would be in the region in a couple of weeks.
"They will be able to use force if and when necessary… in full accordance with international law," he told the BBC's Focus on Africa programme.
He said he did not think the pirates, even though they were well armed and organised, would be a match for the warships.
"If I was a pirate, I wouldn't necessarily jump at the opportunity to take on a Nato frigate or a group of Nato frigates.
"I suspect when it comes to firepower and capability we can hold our own just fine."
Pirates are demanding a $22m (£11m) ransom for the release of the Ukrainian ship, the MV Faina.
The vessel, which was carrying T-72 tanks, rifles and heavy weapons when it was seized two weeks ago, is being held off the coast, near the town of Hobyo.
Piracy off the coast of Somalia is estimated to have cost up to $30m (£17m) in ransoms so far this year, according to a recent report.
Human Rights Watch says Somalia is the most ignored tragedy in the world.