Martin Indyk, former USA ambassador to Israel and former special envoy for Israeli-Palestinian negotiations, said on Twitter Assad appeared to be offering to "get the Iranians to pull back from Golan" Heights, if Israel accepts it as Syrian.
Late past year, the U.S., Russian Federation and Jordan had agreed to create a "de-escalation zone" in southwest Syria, parts of which border Israel.
The secret agreement was hashed out over the phone between the Russian Defense Minister Sergei Shoigu and his Israeli counterpart Avigdor Lieberman. "We believe that there is no room for any Iranian military presence anywhere in Syria", he said.
Sources added that Bolton and Ben-Shabat will also discuss joint military cooperation in countering Iran's presence in Syria.
Prime Minister Benjamin Netanyahu also said in remarks to the Knesset on Monday that Iran should be pressured to leave Syria altogether.
In addition to violence inside Syria, Daraa's location on the border of the Israeli-occupied Golan Heights makes any operation there highly sensitive.
Government forces recently dropped leaflets on rebel-held areas in Daraa, warning of an imminent offensive and urging anti-Assad fighters to lay down their arms.
Israel has been pledging for months to prevent its main enemy Iran from entrenching itself militarily in Syria, where Tehran is backing President Bashar al-Assad's regime. The report said a Jordanian mediator carried messages between the sides.
Israel suspects Syria's ally Iran of seeking to establish a military presence close to territory it controls and has repeatedly struck Syrian and Iranian targets in Syria when it felt threatened.
Sources briefed on the trip told Israel's Channel 10 reporter Barak Ravid that the two officials will be ratifying an existing agreement between Israel and the United States on how to deal with Iran.
Those strikes followed a barrage of some 32 rockets that were fired by Iranian forces in Syria towards Israel's part of the Golan Heights.