SIMI VALLEY, Calif. (Reuters) - The U.S. Navy plans to divest its older model Boeing Co BA.N F/A-18 Hornet fighter jets in coming years and hopes to buy dozens of F/A-18E/F Super Hornets to deal with a shortfall of strike fighters aboard its carriers, a Navy official said.

A F/A-18E/F Super Hornets of Strike Fighter Attack Squadron 211 (VFA-211) is lined up for take off on the flight deck of the USS Theodore Roosevelt (CVN-71) aircraft carrier in the Gulf June 18, 2015. REUTERS/Hamad I Mohammed/File Photo

The plan, which is still being finalized, could be implemented as early as part of the fiscal 2018 budget, said the official, who was not authorized to speak publicly.

“To decrease the strike fighter shortfall and to best prepare future air wings for likely threats we will soon divest from legacy Hornets, look to buy several squadrons worth of Super Hornets and continue with efforts to bring on the F-35 carrier variant,” said the official.

The Navy also plans to field and deploy a new unmanned carrier-based refueling plane, the official said.

Sources familiar with Navy plans say delays in the fielding of the carrier variant of the Lockheed Martin Corp LMT.N F-35 fighter jet, longer-than-expected maintenance times for older model Hornets, and higher usage rates have left the Navy facing a shortfall of about 70 fighter jets in coming years.

If implemented, the plan would provide dozens of new orders for Boeing and keep its St. Louis production line running for several more years.

“We would welcome an opportunity to develop a plan, with the Navy, that would allow us to continue providing the robust capabilities of the Super Hornet well into the future,” said Boeing spokesman Todd Blecher.

The company had suffered a setback last month when Congress failed to include 12 Super Hornets in the fiscal 2017 defense authorization bill, opening a potential gap in the Boeing production line until several foreign orders for Kuwait and Canada are finalized. The $618.7 billion bill was passed Friday by the U.S. House of Representatives, and the Senate is expected to vote on the measure next week.

Navy officials say the jets could still be added to the fiscal 2017 budget as part of a supplemental budget that lawmakers are urging Republican President-elect Donald Trump to submit after he takes office.

Republicans, who will control both houses of Congress and the White House after Trump is sworn in on Jan. 20, see good prospects for raising military spending levels and scrapping a 2010 law that imposed mandatory cost caps on defense spending.

The older model Hornets could be transferred to the Marine Corps, which has faced its own maintenance issues, including a lack of spare parts.