The Vice President of the European Central Bank (ECB), Vitor Constancio has warned that Europe's ageing society needs immigrants to prevent a further squeeze on the continent's workforce.

"This is a very acute problem because for years Europe has been doing a sort of collective demographic suicide," he said during an interview with Reuters.

He continues: "To change the demographic trends, promoting birth is not enough. It also has to be done through immigration. If not, we're creating a great difficulty to growth and to the welfare of future generations."

The Portuguese official called on European leaders to allow people to settle in their countries - he added that high unemployment in some European states has created a "backlash" against immigration - and that high levels of joblessness is "destabilising the continent" - and compromising its "values."

The eurozone's population grew by 0.25% last year, with population levels falling in seven of the 19 nations which make up the monetary union - while the population of the US rose by 0.75%, and Australia grew by 1.4%.

During the wide-ranging interview he also said that the ECB is willing to amp-up its quantitative easing bond-buying programme.

He points out that the ECB has pumped less money into the euro economy than its counterparts in the US, UK and Japan.

When asked about the damage that the tabling of a possible temporary-expulsion of Greece from the eurozone had done to the Union - he said that the proposal was never a realistic possibility:

"There was never any doubt among the majority of member countries (that) the euro is irreversible," he said.

"The actual prospects of that happening was never for real."