(The Hill) — Domestic flight prices have increased 40% since the beginning of 2022 and are expected to rise an additional 10% next month.

Flight booking website Hopper said the price of a domestic round trip is averaging $330, a 7% jump above 2019 costs. International round trips are currently averaging $810, a 25% increase from the start of the year.

The combination of high demand and rising fuel costs is largely driving the price hike for flights.

“A tremendous amount of demand [is] from travelers who have not been able to travel the last two spring and summer seasons,” Haley Berg, an economist at Hopper, told ABC News. “And the second factor is jet fuel. Jet fuel prices are also up 40% since the beginning of the year and up 75% since this time last year. Demand and higher jet fuel prices together are really driving overall domestic airfare up.”

Delta Air Lines, United and Southwest Airlines all announced last month that they would raise prices to cover the increase in fuel costs, with Delta saying it was looking at a 10% jump in airfare.

“We’ve not seen a stronger demand … in my career,” Delta Chief Executive Ed Bastian said.

The news comes after President Joe Biden placed a ban on Russian oil, natural gas and coal imports last month as part of his administration’s response to Russian President Vladimir Putin’s invasion of Ukraine.