The letter, which could be a fabrication, is marked 1 August and was addressed to the Ecuadorian embassy, where Assange has been a resident since 2012.
In an exclusive interview with Colombian broadcaster NTN24, Ecuador's President Lenin Moreno Moreno discussed the conditions in which he would ask WikiLeaks founder Julian Assange to leave the Ecuadorean embassy in London.
The U.S. committee's request comes at a time of growing speculation about Assange's future and his possible ejection from the embassy after six years.
As of Wednesday, both leaders of the Senate intel committee, Sen. The letter says the committee requests Assange make himself available for a closed-door interview "at a mutually agreeable time and location".
"According to Moreno, Ecuadorian authorities are now in talks with Assange's lawyers to work out an agreement that would ensure the security of the WikiLeaks' founder "'in line with the norms of worldwide law".
Ryanair flights grounded as pilots strike
The VNV said it has been negotating with Ryanair over a pay-and-conditions agreement for eight months without making any progress. As Ryanair had already informed passengers of the disruption there was "no one looking desperately for flights".
Pamela Anderson's self-described "romantic connection" with Julian Assange, as reported by Fox News, suddenly spices up the long-running investigation of Wikileaks' connections to Russian interference in the 2016 US election.
However, he would be arrested by British police for breaching bail conditions should he leave the building, and he has always said he fears being extradited to the United States for having published a huge cache of USA diplomatic and military secrets on the WikiLeaks website.
Assange is now without internet access after clashing with the Ecuadorian government for his activities on social media during the USA and Spanish elections.
Since his de-facto house arrest in the embassy, WikiLeaks has continued to draw controversy, publishing then-candidate Hillary Clinton's emails and leaked emails from the Democratic Party's internal servers in 2016.
His testimony could be useful to special counsel Robert Mueller, who is leading the "bipartisan" investigation into Russian meddling Trump has branded a "witch hunt".