Nigerian President Muhammadu Buhari asked the country's parliament to extend his leave from office for medical reasons on Sunday, despite the country's top officials continuing to maintain he is in good health.

His administration released a statement saying he had written to the country's National Assembly, which includes a senate and house of representatives, similar to the United States.

"President Muhammadu Buhari has written to the National Assembly today, February 5, 2017, informing of his desire to extend his leave in order to complete and receive the results of a series of tests recommended by his doctors," the statement said.

The administration has continued to refer to Buhari's leave as a "vacation," but rumors have swirled around the president's health for months. The 74-year-old president spent nearly two weeks in London last summer for an ear infection, and has been in Britain for the past two weeks as well.

He was expected back to work from this leave Feb. 6, but the statement did not say how much extra time away he was seeking.

Just a week and a half ago, Nigerian officials were not only begging the public to not fall into the trap of believing everything they read about the president's health on social media, but also were going out of their way to deny there was any reason for worry.

"There is no iota of truth in the messages being circulated on the health of the President," said Minister of Information and Culture Alhaji Lai Mohamed, in a statement as reported by Reuters. He added that Buhari is "hale and hearty."

Femi Adesina, the special adviser to the president on media and publicity, went even further in an interview with CNBC Africa.

"The president is in London on vacation," Adesina said. "He is in no hospital, and he is not ill."

When pushed by the interviewer about why the president wouldn't make a public appearance or give an interview himself to quell the rumors, Adesina said forcing him to do such a thing would be "infringing on his rights."

An extended leave could hurt "already-shaky confidence" in the president's administration, according to Reuters:

"Buhari's health issues come as investors push the government to allow the currency to float freely, saying it its being kept artificially strong by policymakers. The economy is performing its worst in 25 years."Meanwhile, in the northeast, a humanitarian crisis threatens millions, ridden by conflict with Islamic insurgents Boko Haram."

Buhari declared more than a year ago that Nigeria had "technically won the war" against Boko Haram, but as NPR's Maggie Penman reported last month, even though the country's army celebrated another victory in December, that's doubtful to signal an end to the seven-year conflict that's killed more than 20,000 people:

"Though the president's message was celebratory, there are already reports that insurgents are regrouping in Taraba and Bauchi states, south of their stronghold in Borno state."Copyright 2017 NPR. To see more, visit http://www.npr.org/.