EU foreign affairs chief Federica Mogherini on Wednesday said that European countries where people are growing old fast need immigration to sustain their economy.

Europe can only resolve the migrant crisis through cooperation and not by "closing its doors," Mogherini said as she opened a Europe-Africa meeting on migration in the Maltese capital.

"I believe Europeans should understand that we need immigration for our economies," as the continent's population ages, she said.

"Africa on its side should consider the cost of human trafficking, the loss of human life."

She noted that at least 4,500 people, mainly Africans, drowned or were listed missing at sea last year as they tried to reach Italy.

"We must stop the tragedy at sea and in the desert. Every single day people still die."

Mogherini's statement is in clear contrast to the opinion of far-right European leaders who have publicly aired their opposition to the immigration of non-Europeans into the continent.

French far-right leader Marine Le Pen, one such leader, has emerged as a solid contender in the run-up to the upcoming presidential elections.

Among the main points of Le Pen's election campaign, the anti-immigration rhetoric remains one of the key factors responsible for her increasing public support.