Israel is lobbying the United States to keep Syria weak and decentralized, including by letting Russia keep its military bases there to counter Turkey’s growing influence in the country, four sources familiar with the efforts said.

Turkey’s often fraught ties with Israel have come under severe strain during the Gaza war and Israeli officials have told Washington that Syria’s new Islamist rulers, who are backed by Ankara, pose a threat to Israel, the sources said, Reuters reported.

The lobbying points to a concerted Israeli campaign to influence US policy at a critical juncture for Syria, as the Islamists who ousted Bashar al-Assad try to stabilize the fractured state and get Washington to lift punishing sanctions.

Israel communicated its views to top US officials during meetings in Washington in February and subsequent meetings in Israel with US Congressional representatives, three US sources and another person familiar with the contacts said.

The main points were also circulated to some senior US officials in an Israeli “white paper”, two of the sources said.

All the sources spoke on condition of anonymity due to diplomatic sensitivities.

“Israel’s big fear is that Turkey comes in and protects this new Syrian Islamist order, which then ends up being a base for Hamas and other militants,” said Aron Lund, a fellow at US-based think-tank Century International.

The US State Department and National Security Council did not provide a response to questions for this story. The office of Israel’s prime minister and the foreign ministries in Syria and Turkey did not immediately respond to requests for comment.

It was not clear to what extent US President Donald Trump’s administration is considering adopting Israel’s proposals, the sources said. It has said little about Syria, leaving uncertainty over both the future of the sanctions and whether US forces deployed in the northeast will remain.

Lund said Israel had a good chance of influencing US thinking, describing the new administration as wildly pro-Israeli. “Syria is barely even on Trump’s radar now. It’s low priority, and there’s a policy void to fill,” he said.

Israel has publicly declared its mistrust of Hayat Tahrir al-Sham (HTS), the Islamist faction that led the campaign that toppled Assad and which emerged from a group that was affiliated to al Qaeda until it cut ties in 2016.

Now, Israel is deeply concerned about Turkey's role as a close ally of Syria's new rulers, three US sources said, describing the messages delivered by Israeli officials.