Nigeria faces the "best years" ahead under President Muhammadu Buhari, his deputy promised at the late Wednesday inauguration banquet for his second term -- celebrations which the head of state did not attend.
"On behalf of Mr. President, please accept our deepest gratitude for your support and presence here this evening," Vice-President Yemi Osinbajo told dignitaries, according to an official transcript released Thursday.
"The best years of Nigeria begin today, and by the Grace of God, all of us will live to enjoy the coming years and many more."
The dinner, held in the capital Abuja on Wednesday evening, came hours after Buhari took the oath of office.
The 76-year old leader, in power since 2015 and re-elected in February, has faced repeated questions about his medical fitness.
He has spent several months abroad in 2016 and 2017 for treatment for an unspecified condition.
Buhari surprised some by not making a speech at his swearing in ceremony, held in front of a military parade in the capital Abuja. Officials billed the day as a "low-key" event.
"We are grateful to the ... Nigerian people for trusting us yet again," Osinbajo said. "That trust will not be betrayed."
Buhari spoke in an interview broadcast on state television on Monday, where he vowed once more to tackle crippling security threats and root out corruption.
Presidential official Femi Adesina confirmed that Osinbajo had represented the president at the dinner, adding that Buhari had flown on Thursday to Saudi Arabia for a meeting of the 57-member Organisation of Islamic Cooperation (OIC) in Mecca.
Buhari is expected to address OIC leaders on the ways to "combat common challenges such as terrorism and violent extremism," State House said in a statement.
He is due to return to Nigeria on 2 June.