Brussels, Belgium (BBN)-EU foreign and defence ministers are expected to approve a mission to destroy the boats used by people-smugglers operating in Libya.
At a meeting in Brussels, the ministers will also discuss the mission's command-and-control structure and HQ.
It is part of the EU's response to the vast numbers of illegal migrants from Africa and the Middle East crossing the Mediterranean Sea to reach Europe, reports BBC.
More than 1,800 migrants have died in the Mediterranean in 2015.
This is a 20-fold increase on the same period in 2014.
Some 60,000 people have already tried to make the perilous crossing this year, the UN estimates.
Many are fleeing conflict or poverty in countries such as Syria, Eritrea, Nigeria and Somalia.
'DESPERATE CONDITIONS'
The EU ministers are expected to fine-tune the 28-member bloc's search-and-destroy operations.
Initially it will involve gathering intelligence on the activities of the gangs, but it will also take action against smugglers' boats in international waters, the BBC's Chris Morris in Brussels reports.
Our correspondent says the third and most controversial phase of the mission will be military operations conducted inside Libyan territorial waters and on its coast - in areas controlled by a potentially hostile Islamist militia.
Many of the smugglers operate from Libya, whose UN ambassador has objected to the EU proposals.
EU countries are seeking a UN Security Council resolution that will give legal backing for a mission that allows military operations in Libyan waters.
Its aim, officials say, is to disrupt the business model that makes people-smuggling across the Mediterranean such a lucrative trade.
What that means in practice is that the EU is willing to take considerable risks to destroy boats and infrastructure used by smugglers who are swamping Europe with huge numbers of migrants, our correspondent says.
Italy has proposed that the mission should be led from Rome by Adm Enrico Credendino, who ran the EU's naval mission against piracy off the Horn of Africa in 2012.
A UN mandate that allows EU operations on Libya's coast would require a chapter seven UN resolution and Secretary General Ban Ki-moon has already cautioned against a military solution.
Rights groups, including Amnesty International, are also warning that military action could leave migrants trapped in Libya in desperate conditions.
Italian Foreign Minister Paolo Gentiloni said at the weekend that it was important to have Libyan backing for the operation, particularly the internationally-recognised parliament in Tobruk.
But he pointed out that there was not just one government in Libya, which made the task all the harder.