Oslo [Norway], December 13 (ANI): A US special forces veteran involved in the covert evacuation of Venezuelan opposition leader and Nobel laureate Maria Corina Machado has urged her not to return to Venezuela, describing the rescue as one of the most dangerous missions his team has ever undertaken.

According to CNN, Grey Bull Rescue Foundation founder Bryan Stern said the extraction operation lasted nearly 16 hours and was conducted mainly overnight amid rough seas.

'Overwhelmingly, this is the hardest, most high-profile, most delicate operation we've conducted,' Stern said during a virtual press conference on Friday.

Stern said Machado first boarded a boat from the Venezuelan coast and travelled to a rendezvous point at sea, where he was waiting on a separate vessel.

She transferred to the second boat by Tuesday night and was taken to another location after a tense maritime journey.

Describing the risks involved, Stern said the operation was complicated by Machado's public profile and the attention surrounding her Nobel Peace Prize.

'Because of her face, because of her signature, because the entire Venezuelan intelligence service, the entire Cuban intelligence service, parts of the Russian intelligence, were all looking for her for months, and specifically this week, in particular, because of the Nobel Prize, (it) made this operation significantly more high risk than we've ever done before,' he told CNN.

He noted that while his team has conducted around 800 missions and rescued more than 8,000 people, this was 'the first person that has a Wikipedia page.'

Stern said the boat reached shore early Wednesday morning, after which Machado boarded a flight bound for Norway to attend Nobel Peace Prize-related events and reunite with her daughter after two years.

CNN reported that flight tracking data showed the aircraft departed from Curacao, stopped in Bangor, Maine, and then continued to Oslo.

The Dutch Embassy in Caracas later denied any involvement in her departure.

Machado arrived in Oslo hours after the Nobel Peace Prize ceremony, which her daughter attended on her behalf.

She was greeted by supporters at Oslo's Grand Hotel, who waved from a balcony. She later met Venezuelans who were hopeful of returning to what she described as a future liberated homeland, according to CNN.

The appearance marked Machado's first public sighting in nearly a year.

She had gone into hiding after authorities cracked down on dissent following last year's disputed election, briefly re-emerging at a protest in January opposing the inauguration of President Nicolas Maduro.

Machado's team declined to comment on the rescue operation and did not confirm whether Grey Bull Rescue Foundation was involved.

Machado has previously said she received support from the US government but declined to elaborate.

'One day I will be able to tell you, because certainly I don't want to put them at risk right now,' she said.

Stern said the mission was funded by anonymous donors and, to his knowledge, was not supported by the US government.

However, he acknowledged coordinating with the US military to alert them to his team's presence at sea, citing concerns over ongoing US operations targeting suspected drug trafficking vessels in the region.

'In this case, because the US military is conducting operations in this part of the world, I was worried about - I was deeply concerned about being targeted by the US military,' he said.

'We communicated in such a way that the US government, the US military, knew that we were doing something in the region. They did not know the details of it.'

Asked whether his team would help Machado return to Venezuela, Stern said he strongly advised against it.

'When we were on the boat together, we talked about this, and I begged her not to go back,' he told CNN.

'She's a real hero and icon of mine, and to put her back in harm's way where she may be arrested, killed, tortured, who knows what? - I would really not want to do that.' (ANI)