Oil prices have jumped above $100 a barrel for the first time since Russia's full-scale invasion of Ukraine in 2022, as Iran launched retaliatory strikes at crude-producing Gulf nations.

Pakistan depends on oil and gas from the Gulf and last Friday hiked prices at the pump by about 20 percent, triggering long lines at petrol stations across the country.

Sharif, who described the decision as "difficult", said he was keen to avoid further increases that would hit the population, many of whom live in poverty.

But he said in a televised address that action was necessary, warning: "The energy crisis is the new crisis."

At a meeting on Monday, he said ministers had agreed to try to prevent the situation from worsening and had agreed that government offices except banks should move to a four-day week, with half of all staff ordered to work from home.

School holidays have been extended, with lessons moving online after two weeks.

Fuel allowances for official vehicles except ambulances have been cut by 50 percent for the next two months.

The meeting also agreed salary reductions for government employees, a ban on the purchasing of new equipment and a cut in overseas official travel other than that "needed for the betterment of the country", Sharif said.

Online meetings would be prioritised, he said.