Up to 70,000 migrants and refugees could soon be stranded in Greece, the government has said, as it considers enlisting the help of the army to deal with the emergency.

The alarm was sounded as the EU’s top immigration policymaker said the situation was at risk of becoming uncontrollable unless member states “assume their responsibilities”.

Greece’s migration minister, Yannis Mouzalas, told the Guardian: “In the next month between 50,000-70,000 will come and then I believe [the flows] will stop there.”

Admitting it would “be hard and very difficult”, Mouzalas said it was likely that the Greek armed forces, recently brought in to build “hotspot” screening centres, would be deployed to tackle the crisis.

“Wherever the army is needed it will play a role, just as it does in all western democracies,” he added. “Now we use it to build [camps and centres] and to distribute nutrition; tomorrow we don’t know, we may deploy trucks and use it in several other services.”

Refugees and migrants arrive at the port of Piraeus near Athens. Photograph: Yannis Kolesidis/EPA

Greece’s leftwing Syriza coalition, in power with the small rightwing Independent Greeks party, have so far resisted giving armed forces a more prominent role in handling the influx of people entering Europe across the Aegean from Turkey. In a country that experienced seven years of military dictatorship until 1974, many leftists have expressed consternation.

By Sunday 22,000 people were trapped in Greece with an estimated 6,000 stuck at the Macedonian border after restrictions were tightened – and frontiers effectively sealed to all but Syrians – by Balkan nations along the migrant route.

While Mouzalas insisted the increased numbers would be manageable, the EU’s migration commissioner, Dimitris Avramopoulos, spoke of an imminent humanitarian crisis if the 28-nation bloc continued to indulge in “unilateral actions”.

He said: “There is no point in playing the blame game any more. We simply have to do everything possible to control the situation.”

Enmeshed in its worst economic depression in modern times, debt-stricken Greece has requested emergency aid from the EU. As part of urgent plans to be put into immediate effect, Mouzalas said impromptu camps would be established and tents erected in local sports grounds.

A further four hotspots will be set up in the northern Greek province of Macedonia. In anticipation of the influx, Athens has asked for tents, blankets, sleeping bags, transport vehicles, ambulances and other supplies.

At an economic forum in Delphi, Berlin’s ambassador to Athens, Peter Schoof, announced: “In Germany we have taken the decision that we have to support Greece.”

Germany’s hardline finance minister, Wolfgang Schäuble, hinted that Europe’s powerhouse might be willing to cut Greece some slack as it struggles with the dual task of dealing with the refugee crisis and enacting punishing reforms.

With divisions widening before an emergency EU summit to discuss the crisis on 7 March, anger is mounting, with Berlin enraged at the way Balkan nations led by Austria have closed the refugee transit route.