Interior Minister Joseph Ole Lenku delivered the diplomatic slap when he updated reporters on a government investigation into the assault carried out eight days ago by Islamist militants on the upmarket Westgate centre.
The attack on September 21 was claimed by the Somali Islamist militant group al Shabaab whose fighters fired on shoppers and tossed grenades, leaving a trail of victims of all ages.
Kenyan police, aided by US, Israeli and European experts are still examining the wrecked mall. Mr Ole Lenku said the death toll from the attack still stood at 67, including six Britons and people from France, China, Ghana, Canada, Australia, South Africa, Peru and the Netherlands. Five attackers died.
Mr Ole Lenku expressed Kenya's strong objections to an updated travel advisory issued by the US government to citizens urging them to "evaluate their personal security situation in light of continuing and recently heightened threats from terrorism" in the east African country.
The comments reflect Kenyan concern at the impact the attack - and the travel advisory - could have on the country's £620 million-a-year tourist industry.
"We are concerned by the advisory which is uncalled for, unnecessary, and unfriendly. We believe issuing the travel advisory is counter-productive in the fight against global terrorism," Mr Ole Lenku said.
Kenya had asked the US to lift the warning, Mr Ole Lenku said.
"There have been numerous terror attacks around the globe and traditionally, friendly countries have not done anything to increase the pain of the victim country," he added.