Juncker's plan is expected to relocate 120,000 to 160,000 migrants currently in 'frontline' nations Italy, Greece and Hungary across the EU under mandatory quotas. It comes amid an escalating refugee crisis, with tens of thousands of people making desperate attempts to reach Europe to seek asylum.

Germany, France and Spain would take about 60 percent of those relocated under the quota system - which takes into account countries' GDP, population, unemployment rate and the number of asylum applications it has already processed.

The next biggest intakes would be Poland, the Netherlands, Romania, Belgium and Sweden. Under EU treaties Britain, Denmark and Ireland are not required to participate.

Juncker is expected to reveal the plan in full Wednesday morning as part of his State of the Union speech at the European Parliament in Strasbourg.

Having another go

Less than three months ago, a plan he proposed to redistribute some 40,000 mainly Syrian and Eritrean asylum applicants across the EU was roundly rejected by member states - especially eastern European countries. They argued it could attract more migrants and destabilize countries unused to immigration.

But the attitude among some European leaders towards quotas seems to have softened in recent days. Fears have grown that the crisis may put key European principles like freedom of movement across the EU's internal borders at risk.

In light of concerns expressed by leaders about lax controls at Europe's frontiers, Juncker is also expected to set out plans to speed up the process of identifying 'economic migrants' - and deporting them. The EU was also expected to announce a list of "safe" states whose citizens would stand next to no chance of gaining asylum and would face a "fast-track" towards deportation if denied.

US reaction to Europe's refugee crisis

In Geneva, a United Nations official said it was "not enough" for countries like the US and wealthy Persian Gulf states to give money to help Syrian refugees - they should also take them in.

"Buying your way out of this is not satisfactory," said Peter Sutherland, special representative for migration and development. He emphasized that UN agencies working to support Syrian refugees were well short of their funding needs. Syria's neighbors Lebanon, Jordan and Turkey have taken in a combined four million Syrian refugees.

Authorities in the United States said Tuesday they were considering measures to help refugees fleeing Syria, including increasing the number of refugees the country welcomes and providing help to allies in Europe.

"The White House is going to continue to consider additional steps that we can take to help the countries that are bearing the brunt of this burden," spokesman Josh Earnest said Tuesday.

se/jr (Reuters, dpa, AFP, AP)