Leuthard lined up with other international leaders, including those of France, Canada and Britain, in condemning the move to exit the 2015 accord.
In a tweet on Friday, the Swiss president and energy minister said the decision was “regrettable”.
“As the second largest emitter of CO2, the USA has a responsibility to the rest of the world,” Leuthard said.
She went on to stress that Switzerland remained committed to the Paris Accord to limit global temperatures and greenhouse gas emissions and was still “on course” in meeting its obligations.
Leuthard said Switzerland's move towards reducing fossil fuel consumption and increasing the use of renewable energies was “a huge opportunity” to make the economy more sustainable.
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Contacted by the Swiss news agency SDA, environment ambassador Franz Perrez said he did not believe the long-term objectives of the accord were at risk following the US decision.
It comes less than two weeks after the Swiss voted in favour of a new energy strategy that will gradually replace the power from its ageing nuclear reactors with renewable sources.
The energy strategy 2050 was spearheaded by Leuthard and drawn up partly in reaction to the 2011 nuclear reactor disaster in Fukushima, Japan.
Also on Friday the government issued a draft ordinance aimed at increasing protection of the population in the event of a nuclear disaster in the country.
Produced by a working group set up after the Fukushima disaster, and involving Swiss nuclear power stations, the ordinance foresees tougher measures to deal with a radiation leak.