Buhari made the appeal at the opening of the APC National Caucus meeting at the Presidential Villa, Abuja on Monday.
He said: “We should strictly follow the constitution of the Party in undertaking these party elections.
“We should ensure internal democracy and avoid short cuts and illegal manoeuvres which have characterised the opposition party with the consequences that they are now divided.’’
According to the President, the APC has a history of conducting free and fair primaries whenever consensus about any candidacy is not reached.
He said regardless of the outcomes of the primary processes, “it is imperative that we all work together to ensure the victory of our party.’’
President Buhari thanked the party officials and members for the successes recorded in the 2015 elections.
“We must remember that this resounding success would not have been achieved without the unity of purpose we exhibited in challenging and defeating an incumbent government.
“Those outstanding successes would not have been possible without your hard work, dedication, and above all, sacrifice.
“I wish to individually and collectively thank you all sincerely for believing in me and remaining steadfast party members despite distractions and antics of the opposition,’’ he said.
According to him, such unity is needed now more than ever, if the party hopes to succeed in the looming general elections.
Buhari also urged the caucus and other party members to give the Tinubu reconciliation committee maximum support and cooperation.
“I have appointed a committee, headed by Asiwaju Bola Tinubu, a leader of the Party, to reconcile differences in various states.
“We hope the committee will be given maximum support and cooperation to enable it to satisfactorily carry out its work and get the party united in purpose and in shape for the battles ahead,’’ he added.
The president acknowledged criticisms about the pace of his administration particularly in appointments to boards of government agencies, but said the issue is being addressed, as many of such appointments had been made.
Earlier, the National Chairman of the party, Chief John Odigie-Oyegun, stressed the need for all party members to put aside their differences and work to ensure victory for the party in the 2019 general elections.
Some APC chieftains attending the meeting include Vice-President Yemi Osinbajo, Speaker House of Representatives, Yakubu Dogora, serving and former governors, members of APC National Working Committee, lawmakers, the party’s National Executive Council, and cabinet ministers among others.