GENEVA - The U.N. refugee agency warns that time is running out for more than 500 migrants stranded in the Mediterranean Sea as storm clouds gather and their rescue vessels are denied a safe port of entry in Europe.

Italy and Malta continue to refuse docking rights to two rescue vessels. This despite the deteriorating conditions for 356 refugees and migrants rescued August 9 by the Ocean Viking, a vessel run by the charity Doctors Without Borders, and another 151 people who have been on board the Spanish NGO Open Arms for nearly two weeks.

U.N. refugee agency spokesman Charlie Yaxley says the passengers are in urgent need of disembarkation. He tells VOA storms are coming, so time is running out for a solution to be found.

"The rough seas are expected to intensify during the course of today and into tomorrow. Really, this is a question of how much we are willing to turn a blind eye to the suffering of people who have fled war and violence," he said.

Yaxley says many of the people aboard the rescue vessels come from Somalia, Eritrea, Sudan and other unstable countries. While many others have fled economic hardship rather than conflict, he says they too have suffered appalling abuse--many during their perilous journeys toward Europe and many more in Libya.

He says conditions for refugees and migrants are so abysmal that those rescued at sea should not be returned to Libya, which is not safe.

"People do not choose to risk their lives on these dangerous journeys unless they feel the desperation that their lives are in better hands on the water than on remaining on the land," he said. "The intensifying fighting, the widespread reports of abuses including arbitrary detention means it cannot be considered to have a safe port. Nobody should be returned there."

Yaxley says the UNHCR supports a system whereby European nations share the responsibility of hosting the refugees and migrants with the countries that provide a safe haven to those rescued at sea.

However, anti-immigrant governments in Italy and Malta accuse Europe of leaving them to deal with the refugee crisis on their own. To deter rescues at sea, Italy recently passed a law imposing fines of more than one million dollars on boats conducting these missions entering its waters.