Former Vice President Atiku Abubakar has explained why he could not enter the United States.

There have been concerns that Mr. Abubakar was avoiding a trip to America because he fears a warrant was out for his arrest there.

But Mr. Abubakar, who is expected to run for president in 2019, said in an interview published by The Boss newspaper that he had actually made attempt to visit the U.S. but was denied on administrative grounds.

“I applied, but wasn’t issued a visa. However, they did not decline me categorically either. They’ve only said my application is going through administrative process,” Mr. Abubakar told the paper published by Dele Momodu.

“It is the sole prerogative of America to determine who they want in their country or not. I’m not running away from America,” Mr. Abubakar added.

The former vice-president said such administrative denials were not unique to him, saying President Muhammadu Buhari could not also enter the country for 15 years due to his religious views.

The U.S. Embassy in Abuja did not immediately respond to email seeking comments Saturday afternoon.

Speculation about Mr. Abubakar’s run in with U.S. authorities stemmed from a broadband contract award to iGate, an America company which Williams Jefferson, then U.S. federal lawamker from Louisiana, had interest in.

Mr. Jefferson was said to have used his political influence and friendship with Mr. Abubakar to ensure that the contract went smoothly in Nigeria with intentions to pay some kickbacks to Nigerian officials, including the former vice president.

Mr. Jefferson revealed in a secretly recorded conversation with the FBI that Mr. Abubakar stood to benefit up to $500,000 for helping influence the broadband deal in Nigeria at the time.

Although Mr. Jefferson lost his representative seat and served jail term in America for the deal, Mr. Abubakar was never prosecuted in Nigeria. It is also not clear if Mr. Abubakar was indicted in the U.S over the case.

“On the issue of corruption, I have challenged anyone, anywhere, who has any evidence of corruption against me to come forward. I’m sure they would have combed everywhere trying to find anything incriminating against me, but they have not found it, or they are still searching,” Mr. Abubakar said.

Mr. Atiku, vice-president from 1999-2007, has largely been a businessman since retiring from Nigeria Customs Service decades ago.

He dismissed his critics and contenders as lacking basic entrepreneurial knowledge, hence the reason they despise him for his own business acumen.

“Let any of those who want to compete with me show what they have managed successfully,” Mr. Atiku said.

Mr. Abubakar’s likely 2019 ambition has become increasingly noticeable in his activities in recent months.

Over the past year, he had initiated a slew of political moves to cast himself in a brighter light.

Prominent amongst these is his relentless call for a fundamental restructuring of Nigeria, arguing that the current system is unworkable —a position that Nigerians are buying into in an ever increasing number.

Mr. Abubakar has been described as a serial contender for the presidency, having run in 2007 and 2015 elections, although the 2015 bid ended at primary stage when he lost to Mr. Buhari.

He dumped the ruling All Progressives Congress last week Friday, citing alleged failure by the Buhari administration to improve the quality of life in the country and neglect of the youth in federal cabinet appointment.

His political allies have indicated that Mr. Abubakar was on his way to the opposition Peoples Democratic Party, which has opened its doors to him.

The Minister of Women Affairs, Aisha Alhassan, openly threw her support behind Mr. Abubakar’s presidential bid in September despite the uncertainty that clouds Mr. Buhari’s re-election plans.

Mr. Abubakar also accused the president of sidelining him after contributing immensely to ensure his victory against then-incumbent Goodluck Jonathan in 2015.

The presidency has not reacted to Mr. Abubakar’s criticism.

But Mr. Abubakar’s recent actions have earned him renewed criticism, with many of his adversaries exhuming his past controversies, which include the iGate scandal.