"The Eritrean embassy in Tripoli is going to deliver identity cards to those concerned so that those who want to can stay in Libya," the ministry said, adding that around 400 people were affected.
The International Organisation for Migration confirmed that Libya had agreed to find the Eritreans employment on public works projects.
"These migrants are scared of being repatriated," the inter-governmental organisation's head of mission, Laurence Hart, told AFP.
On Tuesday, Amnesty International called on Libya not to repatriate the Eritreans, who include refugees and asylum seekers as well as migrants, because of fears they could face torture or other ill-treatment as punishment for "betraying" the country or fleeing military service.
The London-based watchdog said that 200 Eritreans had been moved to Al-Birak detention centre in the desert town of Sabha following an escape attempt on 29 June by around 15 of them in the Misratah camp in the north.
"The Libyan authorities must protect these Eritrean nationals and ensure that they are not forcibly returned to their home country, where they would be at serious risk of torture and other abuse," Amnesty's Middle East and North Africa director, Malcolm Smart, said.
"Any forcible return of Eritrean nationals would be a violation of Libya?s obligation not to return any individuals to a country where they would be at risk of torture or other forms of ill-treatment," Smart added.
The action over the Eritrean refugees and asylum-seekers comes amid a row between Libya and the Office of the UN High Commissioner for Refugees over the agency's work in the country.
The UNHCR said last month that it had been allowed to resume part of its work following talks over Libya's initial decision to expel the agency.
But it added that Tripoli was maintaining its accusation that the UNHCR representative had been offering refugee status in exchange for sex.
[readon1 url="http://www.google.com/hostednews/afp/article/ALeqM5jdfQHfHyuQ9O9ty2FC4Oo-ZyiMYA"]Source = AFP[/readon1]