The loan request is to finance projects in the 2020 budget.
The President had asked the Senate to approve N850 billion loan for the Federal Government to enable his regime to fund the 2020 budget.
The Senate President, Ahmad Lawan, read the letter after a closed session with members when the red chamber resumes plenary on Tuesday.
Buhari, according to the official communication, is seeking the approval of the senate to raise a fresh loan of N850bn from the domestic capital market.
The President said the loan would enable his government to adequately finance projects in the 2020 budget.
The Senators wore face masks in the chamber and they also maintained social distancing by keeping two seats between one another.
The President, in the letter, explained that the external borrowing would be made from the domestic capital market instead of the capital international market.
He added that the Minister of Finance, Budget and National Planning, Zainab Ahmed, has been directed to provide further information that may be requested by the upper legislative chamber over the new external borrowing plan.