Germany has decided to start returning newly arrived asylum seekers to Greece starting in mid-March, according to an interior ministry spokesperson, effectively reversing a five-year suspension of such transfers owing to the poor conditions there.

Under the European Union's so-called Dublin rules, would-be refugees must file for asylum in the first member-state of the bloc they enter - often Greece, Italy or Bulgaria.

If asylum seekers have travelled on to other EU nations, they are to be returned to their first port of call.

But that requirement was halted for Greece in 2011, which together with Italy has been the main point of entry for the more than one million migrants who have entered the bloc since 2015, fleeing war and poverty in the Middle East and Africa.

A German interior ministry spokesman told AFP news agency that Germany would reinstate the Dublin rule in two months' time and return newly-arrived asylum seekers to their first EU port of call.

"In line with the recommendation from the European Commission, Germany believes that such transfers will be possible from March 15," said the spokesman, Tobias Plate.

'Historic migration flows'

Germany's decision comes after the EU recommended on December 8 that member states resume sending asylum seekers back to Greece from March next year.

Athens has criticised the EU's assessment, with Migration Minister Yiannis Mouzalas saying the current legal framework was "unable to respond to the historic migration flows and leaves the burden to the member states that migrants first arrive in".

About 62,000 refugees and migrants have been stranded in Greece after a series of border closures further north early last year and the subsequent controversial deal between the EU and Turkey to stem flows.

In recent days, refugees in camps across mainland Greece and Greek islands have struggled as temperatures have sunk as low as minus 18 degrees.

The severe weather had been forecast well in advance, and the Greek government has come under fire for not acting fast enough to ensure that all refugees are adequately housed.

In Moria, a camp on Greek the island of Lesbos, more than 4,500 people who live in tents are among those hit the hardest by the snowy weather.

READ MORE: Stranded and sick, refugees endure harsh Serbian winter

"While thousands of asylum seekers are exposed to bitterly cold conditions and some may freeze to death, politicians are cynically whitewashing the situation in Greece," said Pro Asyl, the German refugee relief group, raising concerns about Berlin's decision to start returning asylum seekers.

"Instead of enforcing Dublin-deportations, it is of crucial importance to comprehensively investigate the abject failure of the system of housing asylum seekers in Greece and to house refugees in humane conditions without delay. Human rights organisations have been working for months to get refugees out of tents and miserable camps."

Pro Asyl also warned that the measure would put the asylum system in Greece, a country still dealing with a crippling financial crisis, under further pressure.

Germany's 2015 decision to open its doors to Syrian refugees, and to effectively suspend Dublin rules for them, brought 890,000 asylum seekers in that year alone.

But the move by Chancellor Angela Merkel has proved controversial, and the government has since sought to bring numbers down.

Last year, the figure dropped sharply to 280,000 arrivals, largely owing to the closure of the Balkan overland route and a fragile EU-Turkey deal to limit the mass influx.

The plan to return asylum seekers to Greece could further slash new arrival figures, ahead of general elections expected in September, when immigration is set to figure as a key issue.

Trapped in cold

More than 361,000 refugees and migrants reached Europe by boat last year, according to the UN refugee agency. In 2015, more than a million made the perilous journey across the Mediterranean Sea.

READ MORE: The refugee crisis and the Greeks - One year on

Closed borders across Europe have left refugees and migrants trapped in difficult humanitarian conditions in the Balkans, Greece and elsewhere.

Rights groups have expressed concern about the fate of refugees and migrants as a wave of cold weather grips the region.