Nigeria has entered into a new agreement with the United Kingdom that will enable Britain to deport thousands of failed asylum seekers and convicted criminals to the West African nation.

The deal was signed by Interior Minister Olubunmi Tunji-Ojo and Home Secretary Shabana Mahmood during President Bola Tinubu’s state visit to the UK, the Home Office announced on Thursday.

The new agreement will also permit the UK to return visa overstayers to Nigeria, giving Britain broad operational flexibility.

It also provides that Nigeria will, for the first time, accept UK-issued letters, alternative identification certificates issued to individuals without valid passports, to enable their repatriation.

Nigeria has in the past used emergency travel documents as supporting identification for undocumented migrants.

According to the Home Office, Nigeria’s agreement to accept UK-issued letters as an alternative helps remove a key obstacle to carrying out returns.

Under the agreement, Nigeria will, for the first time, accept UK-issued letters—alternative identification certificates provided to individuals without valid passports, to facilitate their return.

Nigeria has previously relied on emergency travel documents as supplementary identification for undocumented travellers.

The Home Office said Nigeria’s decision to accept UK-issued letters as an alternative removes one of the major administrative barriers to returning individuals to their home countries.

The start date and duration of the agreement were not disclosed, and it remains unclear whether any financial incentives are attached to the deal.