do the same. He said Kenyans should "move forward as one nation".
Queues at polling stations formed early and some minor stampedes were reported.
The contest pits Mr Kenyatta against his long-time rival, Raila Odinga, and is seen as too close to call.
Mr Kenyatta, the 55-year-old son of Kenya's founding president, is seeking a second and final term in office.
Observers say the leading candidates both avoided inflammatory speeches as polling day drew closer.
In 2007, more than 1,100 Kenyans died and 600,000 were displaced after a disputed election - an outcome neither side wants to see repeated.
This time long, snaking queues were seen at some polling stations, and video footage at one showed people injured on the ground after an apparent stampede.
- Live updates from the polls
- Kenyatta: The digital president
- Odinga: Love him or loathe him
- Full elections coverage
Some polling stations opened late, with operations hampered by heavy rain, the electoral commission reported.
It later announced that voting would be extended in those areas.
But other problems emerged, 25% of polling stations were apparently without mobile phone coverage, meaning that officials would have to drive to the nearest town to send results.
"To my competitors, as I have always said, in the event that they lose, let us accept the will of the people. I am willing, myself, to accept the will of the people," he said in a brief statement.
"Let us pull this country together and let us move forward as one nation."
Opposition leader Mr Odinga cast his ballot in the Nairobi slum of Kibera.
He addressed the public on Monday, raising fears about vote-rigging and claiming the deployment of at least 150,000 members of the security forces was a ploy to intimidate voters.
However, he congratulated Mr Kenyatta on his campaign, describing him as a "worthy opponent".
When the gates did not open at 06:00 as scheduled, some people became agitated and some approached journalists to vent their frustrations.
The gates opened at 06:23 and the already impatient crowd broke from their orderly queue to rush into the school compound.
Once in, they stood in different queues that had been set up based on voters' surnames.
I found myself in the wrong queue so my biometric details were not available in the unique machine used in that stream.
After getting into the right queue, my details were verified and my photo and name were displayed on the machine in a few seconds.
After I voted, my finger was marked with indelible ink. The whole process took about four minutes.
Despite delays and some confusion, the enthusiasm and energy is unmistakable.
Former US President Barack Obama, whose father was born in Kenya, also called for calm.
"The choices you make in the coming days can either set Kenya back or bring it together," he said in a statement.
"As a friend of the Kenyan people, I urge you to work for a future defined not by fear and division, but by unity and hope."
Eight presidential candidates are on the ballot on Tuesday, with polls open until 17:00 local time (14:00 GMT).
No comments: