Among the dead were an executive with Telemundo, the US-based Spanish-language network owned by NBC Universal, and the director of Ecuador's national intelligence service.
The helicopter crashed at 9:13am local time while flying from the Loisaba Conservancy to the Ewaso Nyiro area in Samburu County, according to the Kenya Civil Aviation Authority.
It said in a statement that an investigation was underway.
There were seven people on board — six passengers and the pilot.
Late on Wednesday, David Nkoroi, the police commander for Samburu, told reporters that all seven people on board had died.
In Washington, the State Department said five of those killed were US citizens.
"The US Embassy is in touch with local authorities and is providing consular assistance," it said.
"We extend our deepest condolences to the families and loved ones on their loss."
The identities of the victims were not revealed, but a local television station in Miami, Florida, said that José Suárez, 55, president and GM of several Telemundo stations in Florida, was among those killed.
"We are heartbroken to learn the tragic news that José was killed in a helicopter accident in Kenya," the NBC affiliate in Miami quoted from a joint statement from NBC Universal and Telemundo leadership.
The helicopter crashed in a rugged area in the foothills of Mount Ololokwe, a popular tourist destination in the country, local media reported.
Ecuador confirmed later Wednesday that Michele Sensi-Contugi, director of the country's National Intelligence Centre, died in the helicopter crash in Kenya.
In a statement posted on X, the presidency said: "In this moment of deep sorrow, the government extends its heartfelt condolences to his family, loved ones and close associates".
Sensi-Contugi, a friend and close associate of Noboa, was visiting Kenya as a tourist with his wife, Stephany Hollihan Vasconez, who also died in the crash.
She was a US and Ecuadorian citizen. They are survived by their two children.
Helicopter crashes have happened with increasing regularity in Kenya, which has a vibrant tourism industry that depends on domestic carriers to ferry visitors to distant places like Mount Ololokwe.
In February, a legislator was among six people who died after a helicopter crash in a hilly area of western Kenya.
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