A new steel barrier on Greece's northeastern border with Turkey to dissuade migration will be ready by April, the prime minister's office said Saturday as he visited the area.

"The premier has pledged to visit the area again by April, when the project is expected to be completed," Kyriakos Mitsotakis' office said in a briefing note.

The government is also hiring an additional 400 border guards for the northeastern Evros area, and will upgrade an existing 10-kilometre stretch of border fence, the PM's office said.

The 26-kilometre (16-mile) barrier in Evros was announced after an attempted migration surge encouraged by Turkey in late February and March.

In skirmishes that went on for days, migrants trying to cross the border threw stones at Greek riot police who fired tear gas at them.

Athens said Turkish police and gendarmes tried to help the migrants break through by providing wire cutters and firing tear gas at the Greek border guards.

Ankara said several migrants were killed and injured by live rounds fired from the Greek side, which Athens denied.

Another planned Greek anti-migration deterrent, a controversial 2.7-kilometre (1.7-mile) floating barrier in the Aegean, looks less certain.

Kathimerini daily in August said the coastguard was sceptical about using it to stop migrant boats, and more likely to use the 500,000-euro barrier in anti-pollution training.

"The barrier has been delivered to the coastguard for use as it deems fit," Migration Minister Notis Mitarachi said this week, without elaborating.

Rights groups had criticised the barrier as potentially life-threatening to asylum seekers in overflowing dinghies who often require rapid rescue.