Israel and Lebanon have been at war since 1948, but the countries are close to an agreement that could increase production of natural gas, helping energy-starved Europe.

Officials from the two countries have said they are close to resolving long-running disputes over their maritime borders, which would allow energy companies to extract more fossil fuels from offshore fields in the Mediterranean Sea.

The increased production won’t make up for the gas that Europe is no longer getting from Russia. But energy experts say an Israel-Lebanon agreement should give a vital push to efforts to produce more gas in that part of the world. Over the last four years, energy production in the eastern Mediterranean has been growing as Israel, Egypt, Jordan and Cyprus have worked together to take advantage of oil and gas buried under the sea.

“This is a very important step for the region to come into its own,” said Charif Souki, the Lebanese-American executive chairman of Tellurian, a liquefied natural gas company based in Houston. “Players are finally realizing that it’s better to cooperate than to continuously fight.”

The Israel-Lebanon negotiations will most directly affect the Karish field, which is set to produce gas for Israel’s domestic use. That fuel is expected to displace gas produced from other fields, which can then be exported. The new field is also expected to produce a small amount of oil.

Chevron, the second-largest U.S. oil and gas company, and several smaller businesses are already producing gas from two larger fields off Israel’s coast. That fuel has increasingly replaced coal in the country’s power plants and factories. Israel now has so much gas that it has become a net exporter of energy, sending fuel to neighbors like Jordan and Egypt. Some of that gas has also found its way to Europe and other parts of the world from L.N.G. export terminals in Egypt.

The U.S. government, across several administrations, has encouraged the growth of the gas trade in the region by helping to negotiate deals between countries that have long had tense relations. The Ukraine crisis has accelerated efforts to explore and produce natural gas because of the soaring cost of the fuel in Europe, where countries are desperate to end their dependence on Russian gas.

Chevron and its Israeli partners are discussing the possibility of building a floating liquefied natural gas platform in the Leviathan gas field, Israel’s largest. The companies are expected to make a decision on the project in a few months.

But getting the gas out of the region will not be easy. Floating export terminals are vulnerable to terrorist attack. And, even if they could be adequately secured, the terminals will not be able to process as much gas as the larger coastal facilities used in major gas producers like the United States, Qatar and Australia. Building terminals on land can take several years, if not often longer, because of opposition from environmental and other groups.

“Energy infrastructure offshore is very volatile and vulnerable,” said Gal Luft, a former Israeli military officer who is the co-director of the Institute for the Analysis of Global Security in Washington. “You have to manage risk.”

Theoretically, transporting gas by pipelines would be easier than liquefying natural gas for export before converting it back into gas at its destination. But building long-distance pipelines is expensive and difficult. A long-running conflict between Turkey, Cyprus and Greece, for example, has made constructing a pipeline from Israel to southern Europe incredibly challenging, if not impossible.

Even an Israel-Lebanon border agreement faces risks. Hezbollah has threatened to attack the Karish field, and it sent unarmed drones over it in July; Israeli officials said they had shot down the ‌aircraft.

Still, Israeli and Lebanese officials have said in recent days that they are pressing on with the negotiations, with officials from the Biden administration acting as a go-between, and are close to a deal. The talks gathered momentum during the United Nations General Assembly last week.

Prime Minister Najib Mikati of Lebanon said on Thursday at the United Nations that he was confident about reaching an agreement with Israel. “Lebanon is well aware of the importance of the promising energy market in the eastern Mediterranean for the prosperity of all countries in the region,” he said, “but also to meet the needs of importing nations.”

U.S. and other Western oil companies have long shied away from Israel, in part because they do not want to alienate Arab countries. But, as relations between Israel and countries like Egypt, Jordan and, more recently, the United Arab Emirates have improved more companies have expressed interest in the eastern Mediterranean.

An agreement between Israel and Lebanon could accelerate that trend.

“I think it will appease many minds,” said Leslie Palti-Guzman, chief executive of Gas Vista, a consulting firm. “Companies that have been reluctant to invest could be more incentivized to develop additional projects.”

Gas fields in the Mediterranean are one of several new suppliers that Europe will need as it seeks a long-term replacement for Russian gas. Other suppliers include energy companies operating in the United States, Qatar, Africa, the Caspian Sea and the North Sea.

“There is no silver bullet,” said Paddy Blewer, spokesman for Energean, a London-based exploration company that hopes to begin producing gas in the Karish field. “The East Mediterranean is one of a series of marginal gains that Europe has to look at.”

Energean plans to begin production in the next few weeks, and has said it expects to produce up to 8 billion cubic meters of gas a year by 2025. If it is successful, the company could significantly add to Israel’s output. The country will produce roughly 22 billion cubic meters this year. Once an importer of almost all of its energy, Israel increased gas production by 22 percent in the first half of the year compared with the same period in 2021. It exported roughly 40 percent of its gas, earning the government royalties of $250 million.

The agreement between Israel and Lebanon will also open the way to drilling in Lebanese waters by a consortium led by Eni of Italy and TotalEnergies of France. Lebanese officials view natural gas as a critical financial tool in its attempts to revive the country’s depressed economy. The government has wanted to drill offshore since at least 2014, but disputes with Israel over the border have delayed exploration.

“It’s not for sure Lebanon will find gas,” said Chakib Khelil, a former president of the Organization of the Petroleum Exporting Countries. “But, if they do, Lebanon will get a big boost.”