ISLAMABAD - The Pakistani rupee slumped nearly 6% against the U.S. dollar on Thursday as the cash-strapped country struggles to unlock critical funding from the IMF.

The rupee weakened to a new record low of 283 per dollar, according to Eikon data.

The currency has been sliding after delays in a deal between Pakistan and the International Monetary Fund, which parties have been negotiating since early last month.

A move to a market-based currency exchange rate regime is one of the actions the IMF wants Pakistan to complete to clear its 9th review, which would release a funding tranche of over $1 billion that has been delayed since late last year.

The South Asian economy has been in turmoil, and desperately needs the IMF deal to unlock other bilateral and multilateral external financing.

Pakistan's central bank foreign exchange reserves have fallen to hardly cover three weeks of imports.

Pakistan’s central bank is widely expected to raise its key policy rate by 200 basis points in an off-cycle meeting on Thursday, a Reuters poll showed.

(Reporting by Asif Shahzad in Islamabad and Ariba Shahid in Karachi; Editing by Christopher Cushing and Kim Coghill)