The United States will review soon a list of countries whose air travellers are subject to tighter screening and could remove nations like Nigeria if they are no longer deemed to be security threats, a U.S. official said.

Nigeria and other key allies such as Saudi Arabia and Algeria have voiced their displeasure at being included in the 14-country list, which Washington unveiled last month after a botched Christmas Day attempt to blow up a U.S. airliner.

Passengers travelling from or through the 14 countries to the United States are subject to special pre-flight screening under the measure, including body pat-downs and carry-on luggage searches.

"There is going to be a review soon and if it turns out that the warning is no longer applicable to Nigeria, it would be removed," Johnnie Carson, U.S. Assistant Secretary of State for African Affairs, said on Wednesday in Accra, the capital of neighbouring Ghana.

"The United States has nothing against the people and the government of Nigeria and we still maintain good relationship with that country," Carson told reporters, adding the measure was designed to "create awareness" about possible threats.

Umar Farouk Abdulmutallab, a Nigerian described by U.S. officials as an al Qaeda operative, tried unsuccessfully to detonate explosives hidden in his underwear on a Dec. 25 flight as it approached the U.S. city of Detroit.

The 14 countries on Washington's list are Cuba, Iran, Syria, Sudan, Afghanistan, Algeria, Iraq, Lebanon, Libya, Nigeria, Pakistan, Saudi Arabia, Somalia and Yemen -- many of them key allies in the fight against al Qaeda.

Nigeria, a major oil supplier to the United States, took exception to its inclusion on the list. Nigerians point out Abdulmutallab largely went to school overseas and that he was believed to have been radicalised in London and Yemen.

Africa's most populous nation is particularly sensitive about its international image at the moment, with political uncertainty over the absence of President Umaru Yar'Adua, clashes last month between Christian and Muslim gangs and the threat of a return to violence in the oil-producing Niger Delta.

Nigeria's Information Minister, who has been spearheading a "rebranding Nigeria" campaign since last year meant to shed the country's reputation for crime and corruption, branded the inclusion on the list as "unfair" and warned bilateral relations could be at risk if Washington kept it on the list.

Nigeria's image was further dented this week when al Qaeda's North African wing issued a statement on Islamic websites offering to give Nigerian Muslims training and weapons to fight Christians.

By Kwasi Kpodo (Reuters)