The former Prime Minister, it is understood, also apologised to his colleagues over the manner in which he had handled the issue.
"He felt that talking directly to the President was the most practical thing to do, given the circumstances", said a source, who described the meeting as initially "tense" and devoid of the pleasantries that have characterised previous Nasa get-togethers.
Last Friday, President Kenyatta and Odinga surprised Kenyans including those close to them after their meeting at Harambee House where they resolved to set aside their political differences for the sake of national unity and urged Kenyans to move forward together as a united people.
NASA strategist David Ndii said their move became necessary after their leader Raila Odinga signed a memorandum with President Kenyatta in a move that has kicked off the process of uniting the country.
In a statement read by Mr. Mudavadi, they revealed Mr. Odinga briefed them on the details of his meeting with President Kenyatta and resolved to have their respective parties ratify the decision to work with the government on unity.More news: LeBron James freezes Lakers' entire defence with slick no-look pass
More news: Mkhitaryan scores as Arsenal thrash Watford 3-0
More news: 2nd Package Explosion This Month Kills Teen in Austin
Dr Ndii's announcement comes three days after NASA leader Raila Odinga reconciliation with President Uhuru Kenyatta on Friday that is being seen as the end of their decades-old vendetta.
The People's Assembly was launched by Odinga previous year after he disputed the 2 presidential elections held in August and October 2017.
However, NASA will not stop fighting for electoral reforms and forging ahead with the people's agenda as was made clear by the coalition's principals, said Dr Ndii.
The U.S. had called on Odinga to recognize Kenyatta's leadership so as to create room for dialogue.