Pentagon chief Chuck Hagel met his Israeli counterpart Moshe Yaalon on Monday to put the finishing touches on a major arms deal and for talks on Syria’s civil war and the Iranian nuclear threat.

Speaking at a joint news conference in Tel Aviv, Hagel confirmed the two had finalised details of a multi-billion dollar arms deal which will see Israel receiving an impressive package of advanced US missiles and aircraft.

“Today we took another significant step in the US-Israel defence relationship,” Hagel said, reiterating Washington’s “ironclad pledge” to ensure Israel’s qualitative military edge in a region rocked by turmoil.

“Minister Yaalon and I agreed that the United States will make available to Israel a set of advanced new military capabilities ... including anti-radiation missiles and advanced radars for fighter jets, KC135 refueling aircraft, and most significantly the V-22 Osprey, which the United States has not released to any other nation.”

Hagel arrived in Israel on Sunday at the start of a six-day regional tour, his first since taking over as Pentagon chief two months ago, which was likely to be dominated by concerns over Iran’s nuclear programme and Syria’s civil war.

 Syria was a central part of their talks,

with Yaalon admitting that Israel had already “acted” to stop advanced Syrian weapons from falling into militant hands, in what was seen as implicit confirmation of Israeli involvement in a strike on an arms convoy inside Syria in January. Yaalon said Israel had laid down three “very clear red lines” for the regime of Syrian President Bashar al-Assad, the first of which was “not to allow sophisticated weapons to be delivered or be taken by rogue elements like Hezbollah or other rogue elements.”

“When they crossed this red line, we acted,” he said, in what was widely understood to be the January 30 strike which hit what a US official said were surface-to-air missiles near Damascus that Israel suspected were en route to Lebanese Shiite group Hezbollah.

The second red line was maintaining the calm along the Israeli-Syrian ceasefire line on the occupied Golan Heights, and the third was the transfer of chemical weapons into the hands of militants, which “has not been tested yet,” Yaalon said. Last month, Syrian rebels and the regime traded accusations of chemical weapons use for the first time in the two-year conflict, with similar allegations made by European diplomats in recent weeks. Although Washington is investigating such claims, it has yet to reach a definitive conclusion.  “Currently our intelligence agencies are assessing what happened and what did not happen,” Hagel said.

The White House has warned that use of chemical agents in the Syrian civil war would constitute a “game changer” but Hagel refused to be drawn on any possible US response. “I’m not going to discuss contingency options,” he said. The US defence secretary said he had had “clear, direct conversations” with Yaalon which touched on the threat posed by Iran’s nuclear programme, which Washington and much of the West believes is a drive for a weapons capability, but which the Islamic republic denies. Shortly before landing in Tel Aviv on Sunday, Hagel said the arms deal with Israel sent a “very clear signal” to Iran that military action remains an option to stop it from obtaining nuclear weapons. “I don’t think there’s any question that’s another very clear signal to Iran,” he said. Israel, believed to be the Middle East’s sole if undeclared nuclear power, has refused to rule out a pre-emptive military strike on Iran’s nuclear facilities, and Hagel on Monday reiterated Washington’s credo that “every sovereign nation has a right to defend itself.” Later on Monday, Hagel will meet Israeli President Shimon Peres and then hold talks with Prime Minister Benjamin Netanyahu on Tuesday morning before leaving for Jordan.  He will also visit Cairo on his tour, then Riyadh and Abu Dhabi to finalise details of the elaborate $10 billion arms deal that will also provide sophisticated missiles to Saudi and US F-16 fighter jets to the UAE.