The United States has urged its citizens to reconsider travel to Nigeria, warning of heightened risks from terrorism, civil unrest and kidnapping in Africa’s most populous nation, according to an updated advisory from the Department of State.

The advisory places at least 23 of Nigeria’s 36 states in the highest-risk “do not travel” category, describing security conditions in those areas as unstable and unpredictable. The assessment reflects persistent violence across multiple regions, despite years of security cooperation between Washington and Abuja.

Alongside the warning, the State Department authorised the voluntary departure of non-emergency staff and eligible family members from the US Embassy in Abuja. The decision, framed as a precautionary measure, follows what US officials describe as a deteriorating security environment and the potential for sudden attacks on civilian targets.

The advisory notes that assaults could occur with little or no warning in public places, including markets, hotels, places of worship, schools, government facilities and transport hubs. It also highlights the threat of kidnapping for ransom, a long-running concern in parts of northern and central Nigeria, where armed groups and criminal gangs operate with relative impunity.

In the northeast, Islamist insurgent groups such as Boko Haram and Islamic State West Africa Province continue to mount attacks on civilians, security forces and humanitarian workers, despite sustained military operations. In the north-central belt, including Plateau and Benue states, communities have faced recurrent killings linked to banditry, communal clashes and reprisal violence.

US officials say Washington will maintain security cooperation with Nigeria, including intelligence sharing, training and support for counter-terrorism operations. American assistance has previously included surveillance capabilities and the deployment of US-supplied aircraft and helicopters in missions against insurgent and armed groups.

Nigerian authorities have not issued a formal response to the latest advisory. In earlier reactions to similar notices, officials have argued that foreign travel warnings often overlook improvements in security and risk undermining Nigeria’s efforts to attract investment, tourism and international events.

The State Department currently lists Nigeria under a level 3 advisory, urging travellers to reconsider visiting the country as a whole, while designating the most volatile states as level 4, its strictest “do not travel” classification. The updated guidance is expected to weigh heavily on travel plans for US citizens, aid organisations and businesses with operations in Nigeria.