Two of Israel’s newly purchased F-35 stealth fighter jets touched down at a Negev air force base Monday night, after bad weather delayed the arrival of the planes, touted as the most advanced fighting machines in the world.

The state-of-the-art American-made jets are seen as a significant upgrade in Israeli air power and a sharpening of its military edge in a volatile Mideast.

Prime Minister Benjamin Netanyahu, President Reuven Rivlin and Defense Minister Avigdor Liberman were on hand, along with US Secretary of Defense Ashton Carter and top defense officials, to greet the F-35s on the tarmac of the Nevatim Air Base in southern Israel.

In a speech delivered just before the jets roared into the hangar, Netanyahu thanked Washington for the aircraft, and warned enemies that the “long arm” of Israel’s defense capabilities had been strengthened.

“This long arm was just made longer and mightier today,” he said at the welcoming ceremony. “I want to say clearly — anybody who thinks of attacking us will be attacked. Only strength brings deterrence, only strength brings peace.”

Israel is the first foreign country allowed to purchase the planes, and has agreed to buy a total of 50, at NIS 380 million ($100 million) apiece, from Lockheed Martin.

Prime Minister Benjamin Netanyahu gives a speech during a ceremony upon the arrival of the first two F-35 stealth fighter jets purchased in the United States on December 12, 2016 at the Nevatim Air Force Base in southern Israel. (AFP PHOTO / JACK GUEZ)

Prime Minister Benjamin Netanyahu gives a speech during a ceremony upon the arrival of the first two F-35 fighter jets purchased from the US on December 12, 2016 at the Nevatim Air Force Base in southern Israel. (AFP PHOTO / JACK GUEZ)

Rivlin told politicians and top IDF brass attending the ceremony that the “more than 22 tons of flying steel” in each F-35 would “change the Middle East.”

“The aircraft will change the rules of the game,” he added. “It will change the scope of our activities. Our enemies already know that it doesn’t pay to attack Israel.”

Carter said strong US support of Israel was due in part to the “many threats that face you every day.”

“There’s no better symbol of that relationship than the F-35,” he said. “Together, we will dominate the skies.”

“We’ll continue to provide Israel with the most advanced capabilities, including more F-35s, to sharpen Israel’s military qualitative edge,” Carter continued. “With the turmoil in the region, we’re more dedicated to Israel’s security today than ever before.”

Known in Hebrew as the “Adir,” meaning mighty or great, the F-35s touched down in Israel shortly after 8:15 p.m. after fog kept the planes grounded in Italy for several hours Monday afternoon.

Defense officials insisted that while the planes could operate in bad weather, flying in fog is avoided in non-operational circumstances, and said they weren’t keen to risk flying the state-of-the-art machines through cloudy skies to the ceremony.

US Secretary

US Secretary of Defense Ashton Carter and Defense Minister Avigdor Liberman stand in front of the F-35 fighter jet at the Nevatim Air Force Base in southern Israel on December 12, 2016

As a result, they overshot their scheduled 2 p.m. arrival at Nevatim by some six hours. It was only at around 4 p.m. that the planes finally took off — and even then only after officials said they were considering scrapping the ceremony altogether for a clearer day.

Some 4,000 people had been expected to watch the landings, but the crowds thinned as the landing was delayed, leaving only around half the seats full by nightfall.

After they touched down, the jets were ceremoniously adorned with IAF markings to symbolically mark the start of their service. IAF Maj. Gen. Amir Eshel said the aircraft would “become more and more blue and white with [their] operation.”

The state-of-the-art F-35 is poised to become a central pillar of Israel’s air strategy, a senior air force official told reporters last month. The stealth fighter is considered one of the most advanced aircraft in the world, capable of taking on most missile defense batteries, including the Russian S-300, which was recently acquired by Iran, and which has been used in Syria, where Israeli planes have recently reportedly flown sorties.

Prime Minister Benjamin Netanyahu at a ceremony for the new F-35 Adir stealth fighter jet at the Nevatim Air Force Base in the Negev Desert. December 12, 2016. (Kobi Gideon/GPO)

Prime Minister Benjamin Netanyahu at a ceremony for the new F-35 Adir stealth fighter jet at the Nevatim Air Force Base in the Negev Desert. December 12, 2016. (Kobi Gideon/GPO)

Fog wasn’t the only thing to overshadow Monday’s welcoming ceremony. Earlier, US President-elect Donald Trump lashed out at costs of the fighter jet program on Twitter.

“The F-35 program and cost is out of control. Billions of dollars can and will be saved on military (and other) purchases after January 20th,” Trump said, referring to his inauguration day.

Lockheed Martin’s stock tumbled 4.3 percent shortly after the tweet, which prompted a response from the company.

With a current development and acquisition price tag of $379 billion for a total of 2,443 F-35 aircraft — most of them destined for the US Air Force — the plane is the most expensive in history.

Once servicing and maintenance costs are factored in over the aircraft’s lifespan through 2070, overall program costs are expected to soar to $1.5 trillion.

Speaking at the landing site in southern Israel, Jeff Babione, Lockheed’s program manager for the F-35s, told journalists that the planes represented a good deal.

“It’s great value and I look forward to any questions that the president-elect may have,” he said.

Times of Israel staff and AFP contributed to this report.