BUENOS AIRES- Argentina's government is set to send a bill to Congress on Thursday to formalize a deal with the International Monetary Fund (IMF) to restructure over $40 billion in debt, the head of the lower Chamber of Deputies and the government said.

Argentina's Congress needs to approve the agreement struck between the government and the IMF, following more than a year of winding talks that have weighed on bond prices and limited the grain-producing country's access to international credit.

Once approved in Congress, the deal would also need sign-off from the IMF board.

"The law that enables the treatment of the Memorandum of Understanding with the IMF for its approval or rejection will formally enter into this Chamber," the head of the lower house said in a statement late on Wednesday.

Presidential spokeswoman Gabriela Cerruti said on Thursday she hoped the bill would go before Congress "within hours", adding the toughest area to agree had been how to raise energy tariffs, kept low by subsidies of some $11 billion last year.

"The tariff issue was one of the most discussed and intensely negotiated," she told a press conference.

"But an understanding and a path have been achieved that take care of the most vulnerable and makes headway on the construction of reasonable tariffs that allow us to focus spending to generate employment and boost the economy."

The step forward in Congress comes as Argentina races to finalize a deal with the IMF ahead of a payment cliff this month where it faces a maturity of some $2.8 billion.

President Alberto Fernández said on Wednesday in his opening speech for ordinary sessions of Congress that if the agreement is approved, the country would begin making payments to the IMF in 2026 and complete repayment by 2034.

In January, Argentina's government announced that it had reached an understanding in principle with the IMF to replace a failed $57 billion loan from 2018. IMF head Kristalina Georgieva said then that there was still much work to be done.

(Editing by Bernadette Baum)