Saudi Arabia has pledged investment deals worth $20bn (£15.5bn) with Pakistan which is seeking to bolster its fragile economy.
It comes as part of a high-profile Asian tour by the kingdom's Crown Prince Mohammed bin Salman.
Pakistan urgently needs to address a balance of payments crisis and is looking to international backers for support.
The deals include an $8bn oil refinery in the key port city of Gwadar.
The two sides signed several other provisional agreements and memorandums of understanding in the energy, petrochemicals and mining sectors, according to reports.
"It's big for phase one, and definitely it will grow every month and every year, and it will be beneficial to both countries," the crown prince said.
Pakistan is desperate for cash. The south Asian country's central bank has only $8bn left in foreign reserves and faces a balance of payments crisis.
Prime Minister Imran Khan has been seeking help from friendly countries in order to cut the size of the bailout package his country is likely to need from the International Monetary Fund, under very strict conditions.
The country is seeking its 13th bailout since the late 1980s and Saudi Arabia has already provided a $6bn loan.
Pakistan is the first stop on an Asian tour by the crown prince, known as MBS. He is scheduled to be in India by Tuesday and will visit China on Thursday and Friday.
BDST: 0938 HRS, FEB 18, 2019