Though NATO ships have successfully delivered humanitarian supplies to Somalia, they have not been able to stem the upsurge in pirate attacks on foreign shipping in one of the most important shipping lanes in the world.
Solana said the EU warships will arrive Monday, and the hand-over with the NATO force will take place Dec. 15.
"These tasks will be done with very robust rules of engagement," Solana told reporters on the sidelines of a meeting of NATO foreign ministers in Belgium.
On Tuesday, the U.N. Security Council extended for another year its authorization for countries to enter Somalia's territorial waters, with advance notice, and use "all necessary means" to stop piracy and armed robbery at sea.
Somalia has not had a functioning government since 1991, and pirates have taken advantage of the country's lawlessness to launch attacks on foreign shipping from the Somali coast.
Associated Press writers Slobodan Lekic in Brussels, Belgium and Mohamed Olad Hassan in Mogadishu, Somalia contributed to this report.