Indonesia’s central bank may keep its benchmark interest rate at a four-year high to preserve the rupiah despite the Federal Reserve’s expected monetary tightening.

On Tuesday, Bank Indonesia will keep its reverse repurchase rate at 5.75%.

Policymakers may emphasize the rupiah over Indonesia’s slow disinflation before Thursday’s key Fed meeting, which will raise borrowing prices by another quarter-point. Given a dip in foreign reserves, narrow interest rate differentials, and a shrinking trade surplus.

BI may risk moving against the rupiah, which is down 0.2% this month.

Bank Indonesia’s new export profits guideline requires at least 30% of foreign exchange proceeds to be kept onshore for three months, strengthening the rupiah.

The central bank supports secondary market short-term bond yields.

The central bank will cut rates next, but when is unknown.