BERLIN (Reuters) - Europe will set Greece a deadline of May 12 to register all migrants in an orderly fashion or face more border controls, Migration Commissioner Dimitris Avramopoulos told a German newspaper on Friday.

Greece has been the main gateway for nearly a million migrants who have crossed the Aegean Sea from Turkey over the past year on their way to wealthier northern Europe.

The influx has prompted Austria and others along the Balkans migration corridor to impose restrictions on their borders, meaning at least 30,000 people fleeing conflict of poverty in the Middle East are now trapped in Greece.

"Greece will have until May to protect its external borders," Avramopoulos, a former Greek government minister, told Die Welt newspaper.

"We will take stock of the situation on May 12. Should we see no success by then we will not hesitate to create requirements so that border controls in Europe can be extended," he said.

Avramopoulos told the paper the aim was to lift all border controls that have been instated as a result of the migrant crisis within the passport-free Schengen zone by November.

The EU Commission also plans to present initial plans to reform the Dublin regulation that states that asylum requests be handled where asylum is first claimed in mid-March.

"We are sticking to plans for a permanent distribution mechanism for refugees. It will be associated with the Dublin reform plans. In addition, we will present plans on how asylum standards in Europe can be further harmonized," he said.

Some European Union states in eastern Europe have opposed mandatory quotas to redistribute migrants across the 28-nation bloc.

(Writing by Caroline Copley; Editing by Alison Williams)