Israel's David's Sling missile defence system has passed final tests and should be ready for deployment next year as part of the country's efforts to defend against regional threats, officials said Monday.

The medium-range interceptor, developed with United States backing, is due to be handed to the Israeli air force "at the end of the first quarter of 2016," said Yair Ramati, head of the Israel Missile Defence Organisation.

David's Sling is designed to fill the gap between the longer-range Arrow missile defence system and the shorter-range Iron Dome interceptor.

It was developed by Israel's Rafael Advanced Defence Systems and US company Raytheon.

Earlier this month, Israel also announced that it successfully tested the Arrow 3 interceptor, designed to shoot down missiles above the atmosphere.

The tests come with Israel saying it faces threats from regional enemies including Iran and Hezbollah.

Monday's announcement also followed the killing of a Lebanese militant in Syria at the weekend in what Hezbollah described as an Israeli air strike. Israel has not claimed responsibility.

In an apparent response, at least two rockets were fired into Israel from Hezbollah's south Lebanon heartland, with no casualties reported. The Israeli military said it responded with "targeted artillery fire".

Officials stressed that Monday's David's Sling announcement was not linked to the weekend incidents, with the programme long in development.