The heist was "a very rare act that happened in a private space", Hidalgo said in a statement.
Tourists "can come to the French capital, visit and relax in good security conditions," the Socialist mayor said.
Hidalgo said she was confident police would "rapidly identify and apprehend" the five assailants disguised as police officers who tied up and robbed the reality television star at gunpoint at her luxury residence in a chic Paris district in the early hours of Monday.
The French capital has seen a spate of robberies at top-end jewellery stores in the same area.
The Kardashian robbery came as Paris faces declining tourist numbers over security jitters, in particular since the jihadist attacks of November 2015 that killed 130 people.
Hidalgo's political rival Nathalie Kosciusko-Morizet told French radio that the robbery showed that the capital faced "a general security emergency".
The city authorities "are not reactive enough," said Kosciusko-Morizet, an outside contender for the presidential nomination of the right-wing Republicans party.
France has suffered a seven percent drop in tourist visitors since January, according to official figures released in August.
The number of visitors from the United States and Japan has dipped in particular.
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