The European Union's border agency Frontex is to send its ships further into the Mediterranean Sea in response to a deadly exodus of migrants leaving Libya.

EU migration spokeswoman Natasha Bertaud said Friday that the area of operations "will have to be extended."

She said a new operational plan for Frontex's Triton mission will be agreed with Italian authorities and that this "will be ready in the coming days."

EU leaders on Thursday pledged to double the size of Triton and triple its budget but refused to allow it to do active search and rescue work.

Critics say Triton is ineffective in dealing with the migrant influx because its mandate restricts its tasks to 30 nautical miles from land and does not allow it to approach the Libyan coast.