The US military will deploy additional warplanes and naval vessels to the Middle East, the Pentagon said, as Washington seeks to bolster defenses following threats from Iran and its allies Hamas and Hezbollah.

The United States is preparing for Iran to follow through on its promise to respond to the killing of Hamas leader Ismail Haniyeh, one of a series of assassinations of senior officials of the Palestinian militant group as the war between Israel and Hamas in Gaza continues to rage.

US Defense Secretary Lloyd Austin has approved sending additional cruisers and destroyers – capable of shooting down ballistic missiles – to the Middle East and Europe. An additional fighter squadron will also be sent to the Middle East.

Austin ordered adjustments to U.S. military deployments designed to improve protection of U.S. forces, increase defense support for Israel and ensure the U.S. is prepared to respond to a variety of scenarios, the Pentagon said.

The Pentagon statement added that it will increase readiness to deploy more ground-based ballistic missile defense systems.

The US military also stepped up deployment ahead of April 13, when Iran launched an attack on Israeli territory with drones and missiles. In that time, Israel has successfully shot down nearly all of its estimated 300 drones and missiles with the help of the United States and other allies.

Biden discussed new US military defense deployments to support Israel against threats such as missiles and drones in a phone call with Netanyahu on Thursday, the White House said.

Iran and Hamas blamed Israel for the killing and vowed to take revenge on their enemy. Israel has neither claimed nor denied responsibility for the deaths.