LONDON - The International Monetary Fund's staff will brief the executive board on Argentina on Friday after the country requested to ease foreign reserves targets for this year linked to its $44 billion loan program, a source with direct knowledge told Reuters.

IMF staff and Argentine authorities reached a staff-level agreement this week on the fourth review of the country's extended fund facility and formalized a request to revise net international reserves targets Argentina is struggling to hit.

The South American country, the largest borrower from the IMF by far, is battling against a severe drought that has hammered its soy and corn crops, its main exports, knocking billions of dollars off expected foreign currency income.

The staff briefing to the board reflects the additional complexity of getting the executive's approval for the staff-level agreement following the request to ease economic targets which, if met, trigger payouts.

The source, who asked not to be named, said the briefing was part of the process before the sign-off of a program review when it involved requesting changes on measurable conditions for lending, known as quantitative performance criteria.

A spokesperson for the IMF didn't immediately reply to a request for comment during early U.S. hours.

Argentina's low net reserves, estimated at $4.2 billion at the end of February by Buenos Aires-based firm FMyA, threaten its ability to meet payments and avoid a 10th sovereign default after a major restructuring with creditors in 2020.

The flow of dollars has stalled due to the worst drought in over 60 years hitting crops, while high energy import prices in recent years soaked up more foreign currency.

Under the third program's review, Argentina was set the target of increasing net reserves by $5.5 billion by the end of March and by $9.8 billion by the end of the year. Neither the IMF nor the government has made public the planned new targets.

(Reporting by Jorgelina do Rosario, editing by Adam Jourdan and Susan Fenton)