WASHINGTON — The Pentagon and its top weapons supplier agreed on the lowest set of prices for the F-35, the US's most expensive weapons system, since the program began in 2001.

On Friday, the F-35 Joint Program Office released the finalized price for the most recent production contract for America's fifth-generation stealth fighter. The 10th Low Rate Initial Production, or LRIP-10, contract for 90 F-35 jets came in $728 million less than LRIP-9.

In a statement from the defense giant, Lockheed Martin acknowledged President Donald Trump's recent role in the F-35 program.

"President Trump's personal involvement in the F-35 program accelerated the negotiations and sharpened our focus on driving down the price," the statement said. "The agreement was reached in a matter of weeks and represents significant savings over previous contracts."

On Monday, Trump announced that the latest contract with Lockheed Martin for the F-35 would be reduced by $600 million.

And though it would appear that Trump, after publicly criticizing the crown jewel in the defense giant's portfolio, is the reason for the savings, the price reduction was in the works.

In a December 19 briefing, Lt. Gen. Chris Bogdan, head of the F-35 Joint Program Office, said the price in LRIP-10 would be reduced "significantly."

"I fully anticipate that when we do settle LRIP-10 you'll see all three variants — the A, the B, and the C — come down in price significantly," Bogdan said. By "significantly," Bogdan said he meant "somewhere on the order of 6 to 7 percent per airplane, per variant."

An aviation boatswain's mate maneuvers BF-04, front, the Marine Corps' variant of the F-35B, after a vertical landing aboard the amphibious assault ship USS Wasp. US Navy

The finalized price for LRIP-9, which took 14 months of negotiations between the Department of Defense and Lockheed Martin, for 57 F-35 jets was valued at $6.1 billion.

The unit price for an F-35A — including aircraft, engine, and fee — is $102.1 million. If you take the 6 to 7 percent reduction into account, the savings on LRIP-10 are ballpark to the price point laid out by the Joint Program Office in December.

Most notably in LRIP-10, the total price for an F-35A is below $100 million for the first time.

The LRIP-10 contract includes 55 jets for the US and 35 for seven international partners and foreign military sales clients.

The following is a breakdown of the unit price per variant in 2017 dollars, including aircraft, engine, and fee.

Here are the price tags for the latest batch of F-35s:

• F-35A model aircraft: $94.6 million a jet

• F-35B model aircraft: $122.8 million a jet

• F-35C model aircraft: $121.8 million a jet

Deliveries for these 90 aircraft will begin in early 2018.