Israel may play a frontline role in the international coalition forming against Islamic State – the jihadi group sweeping through Iraq and Syria in a bid to reinstate a new caliphate in the Middle East. As world powers unite around a US-led plan for military action to topple the militant group, Jerusalem is signaling that if Islamic State expands to Jordan – Israel will not hesitate to act."We will use any means necessary," a senior Israeli official told Channel 2 television. "Let me make this clear: If Islamic State reaches Jordan we will take action."The official praised President Barack Obama's call for action and said airstrikes are already making progress in Iraq. Thanks to the US air campaign, "Kurdish forces are able to take back Islamic State strongholds," he said. High-level talks between Israel and the US, currently underway in Washington, are largely focusing on the terror threat. A delegation headed by Strategic Affairs Minister Yuval Steinitz, which includes Mossad officials, the Israel Atomic Energy Commission, and the Defense and Foreign Ministries, left for the US capital earlier this week for discussions on regional crises as well as the looming threat of Iran’s nuclear program.The official's comments come as US intelligence upped its estimates of the number of Islamic State militants currently fighting in Iraq and Syria. It is now believed that between 20,000 and 31,500 fighters are in the ranks of Islamic State, compared to the previous estimate of about 10,000.