BRUSSELS (AP) -- The number of migrants trying to reach Europe through the Mediterranean will remain high this year, with more expected to arrive through Spain, the head of European Union border agency Frontex warned Tuesday.
Fabrice Leggeri told reporters that "the irregular migration pressure on the southern borders in the Mediterranean will remain at a very high level."
He said that "especially the western Mediterranean route is under scrutiny." About 21,000 unauthorized migrants - mostly from Morocco, Algeria and Guinea - entered Spain that way in 2017.
Leggeri said overall numbers have decreased since 2015, when 1.8 million people entered Europe, but migrants are finding new ways to cross borders, and forged documents are a major challenge.
Crossings into Greece are down 80 percent from last year, but he said "the pressure remains at a high level."
Turkey, he said, is trying to stop people leaving for Greece, but criminal gangs are piling on pressure "because this is some kind of pull factor for irregular migrants if they know that criminal networks can help them."
Leggeri expressed concern that EU countries are sending fewer unauthorized migrants home.
"The number of return decisions made by member states has slightly decreased, and this will be a challenge," he said.
That said, Frontex organized more than 340 flights to take people back to their home countries last year, twice the number in 2016.
Mediterranean crossings from Libya, the main jumping off point for Europe via Italy, have gone down.
But Leggeri said that security in the conflict-torn country, where thousands of migrants have been held in over-crowded detention centers, remains a major problem.
"The situation in Libya is not acceptable from a humanitarian perspective," he said. "I wouldn't sign an operational plan saying that rescued migrants should be disembarked to Libya."