ISLAMABAD, Pakistan — Saudi Arabia’s crown prince has pledged $20 billion worth of investments in Pakistan to shore up the country’s struggling economy while strengthening bilateral ties at a time when Islamabad is trying to revive its global standing.

The pledges made Sunday evening — about double what had been expected — would also help Saudi Arabia’s economy by setting up infrastructure, including an oil refinery, to secure Pakistan as a market for Saudi crude oil. The promised investments are nonbinding, however, and whether they will materialize remains to be seen. Riyadh has a long history of over-promising to please allies.

Kicking off a tour of Asia with a visit to Pakistan this week, the Saudi crown prince, Mohammed bin Salman, held separate meetings with Pakistan’s prime minister, Imran Khan, and the country’s army chief, Gen. Qamar Javed Bajwa, endorsing the country’s two levers of power. Pakistani security officials gave glowing reviews of the trip, which they said was an important opportunity to strengthen military ties with Saudi Arabia, a relationship that has come under strain in recent years.

Mr. Khan and General Bajwa met Prince Mohammed as his plane landed at Islamabad’s airport Sunday night to a 21-gun salute, and the prime minister then personally drove the prince to the capital in his Mercedes sedan.