(The Hill) — Delta Air Lines CEO Ed Bastian warned that the airlines’ U.S. ticket prices could increase between 5 and 10 percent given the recent spike in oil prices amid the Russian invasion.

The surge in fuel costs for a U.S. domestic flight “is probably about $25 on a ticket, that could be anywhere between 5% to 10% at these high levels of oil … and international [flights] will be a bit higher than that,” Bastian told the BBC in an interview published on Thursday.

The British broadcaster said that in addition to raising the price of U.S. tickets, Delta is planning to implement an added fuel fee for international flights to combat the rising oil prices. 

Other airlines, such as AirAsia, Emirates and Japan Airlines, have also taken similar steps to combat rising fuel prices by adding fuel surcharges.

This comes as gas prices have hit a 14-year high amid Russia’s invasion of Ukraine, which began over three weeks ago; the national average gas price in the U.S. on Thursday was $4.289, according to AAA.

The U.S. last week announced it would be banning Russian imports of oil, natural gas and coal as a way to further economically isolate Russia. Americans have indicated in polls that they support the move even if it leads energy prices to increase.

The U.S.’s 12-month rate of inflation reached a 40-year high in February, according to data released last week by the Labor Department, with the department saying the spike was driven mostly by rising prices for gasoline, housing and food.

This also comes as some airlines have sought to avoid flying over Russian airspace or have had to reroute their flights due to the conflict, which can also incur additional expenses for a carrier, according to The Wall Street Journal.