UNHCR also reiterated its call to countries to make it easier for refugees to move legally across borders, including through family reunification, to reduce their need to set off on dangerous land and sea journeys in the first place.

The UN agency has repeatedly lambasted countries which close their doors to desperate refugees and in particular European nations that have left migrants stranded at sea for long periods of time and supported repatriation to chaos-wracked Libya.

The UN Human Rights Committee meanwhile faulted Italy on Wednesday for failing to protect the lives of more than 200 migrants, including 60 children, who died in a 2013 shipwreck.

The case was brought by three Syrians and a Palestinian who survived the sinking of the ship, which was carrying more than 400 people.

The committee of independent experts said Italy had failed to respond promptly to a number of distress calls from the sinking boat.