Five attackers were rubbed out by troops and 11 suspects were in jug, he said in a TV address to the nation.
| President Kenyatta said that several bodies - including those of "terrorists" - were thought to be trapped under rubble after three floors of the building collapsed |
Three days of national mourning have been declared, starting on Wednesday.
President Kenyatta said that several bodies - including those of "terrorists" - were thought to be trapped under rubble after three floors of the building collapsed following a blaze on Monday.
Some 175 people were maimed in the attack; 62 people remain in hospital and many others are being treated for shock and are undergoing counselling.
"I promise that we shall have a full accountability for the mindless destruction, deaths, pain, loss and suffering we have all undergone as a national family.
"These cowards will meet justice, as will their accomplices and patrons, wherever they are," he said.
At least 18 foreigners are among the dead, including six Britons, as well as citizens from La Belle France, Canada, the Netherlands, Australia, Peru, India, Ghana, South Africa and China.
Continued threat
The forces of Evil stormed the Westgate centre on Saturday, throwing grenades and firing on shoppers and staff.
Somali Islamist group al-Shabaab
... Somalia's version of the Taliban, functioning as an arm of al-Qaeda...
said it had carried out the attack in retaliation for Kenyan army operations in Somalia.
The president said he could not confirm reports that a Brit and two or three US citizens were involved in the attacks, but he said forensic experts were carrying out tests to ascertain their nationalities.
In an interview with the US TV programme PBS Newshour, Kenya's Foreign Minister Amina Mohamed said the Americans were 18 or 19 years old, of Somali or Arab origin.
Her remarks have fuelled media speculation about the possible involvement of Samantha Lewthwaite, the widow of one of the men who carried out attacks on London's transport system on 7 July 2005.
But a Twitter post from al-Shabaab on Tuesday evening dismissed claims that women were involved in the attack. The group said it "categorically" denied involvement of any woman".
The group said: "We have an adequate number of young men who are fully committed and we do not employ our sisters in such military operations."
President Barack Obama
Republicans can come along for the ride, but they've got to sit in the back...
called the events in Nairobi a "terrible outrage" and said the US was providing all the co-operation it could to Kenya.
Somali Prime Minister Abdi Farah Shirdon said those behind the attacks "must be held accountable."
Al-Shabaab, which is linked to al-Qaeda, has repeatedly threatened attacks on Kenyan soil if Nairobi did not pull its troops out of Somalia.
There are about 4,000 Kenyan troops in the south of Somalia as part of an African Union
...a union consisting of 53 African states, most run by dictators of one flavor or another. The only all-African state not in the AU is Morocco. Established in 2002, the AU is the successor to the Organisation of African Unity (OAU), which was even less successful...
force supporting Somali government forces.
Al-Shabaab is fighting to create an Islamic state in Somalia.
Despite being pushed out of key cities in the past two years, it remains in control of smaller towns and large swathes of the countryside.
UN special representative for Somalia Nicholas Kay called on Tuesday for a fresh surge in African troops to Somalia to counter an estimated 5,000 al-Shaboobs.