Kenyan opposition leader Raila Odinga has pulled out of October's election re-run.
Mr Odinga said his withdrawal would give the electoral commission enough time to introduce reforms that will help deliver a more credible election.
The Supreme Court annulled the result of the original 8 August poll, which saw Uhuru Kenyatta declared winner, after finding irregularities.
But Mr Kenyatta says he is ready to proceed with the new vote as planned.
The country's electoral commission said Mr Kenyatta had won the August vote by a margin of 1.4 million votes – or 54% of the total, compared to Mr Odinga's 44%.
Kenya's vice-president, William Ruto, has now called on the commission to declare Mr Kenyatta president as a result of Mr Odinga's announcement.
The election re-run was due to take place on 26 October, but Mr Odinga said on Tuesday: "We have come to the conclusion that there is no intention on the part of the IEBC [electoral commission] to undertake any changes to its operations and personnel… All indications are that the election scheduled for 26 October will be worse than the previous one."
As a result, he said, "considering the interests of the people of Kenya, the region and the world at large" it was best that he withdrew from the race.
Mr Odinga's coalition party believes the election will have to be cancelled as a result of his withdrawal, allowing "adequate time to undertake the reforms necessary to conduct an election that is in strict conformity with the constitution, the relevant laws and the constitution".
But Mr Kenyatta, speaking at a rally in the southern town of Voi, said: "We have no problem going back to elections. We are sure we will get more votes than the last time."
He added: "We are also telling him it is the people's right to choose their leader. It is their sovereign right to choose their leader of choice."/BBC/