Iran's military ambitions are likely to figure high in President Joe Biden's meetings with Israeli and Saudi leaders on a trip to the Middle East, as Tehran's expanding missile arsenal bolsters its regional armed power.
A day after Tehran and Washington resumed indirect talks to salvage a 2015 nuclear deal in February, Iran unveiled a new domestically-made missile with a range of 1,450 km (900 miles).
State TV displayed the new surface-to-surface "Kheibar Shekan" (Kheibar buster) missile, which refers to an ancient Jewish oasis called Kheibar in the Arabian Peninsula's Hijaz region that was overrun by Muslim warriors in the 7th century.
The move highlighted the Islamic Republic's determination to project military clout as world powers attempt to curb its missile program and revive limits on its uranium enrichment, a possible pathway to nuclear weapons.
Israel sees Iran as an existential threat. But Iran says its ballistic missiles, with a range of up to 2,000 km (1,200 miles), are an important deterrent and retaliatory force against the United States, Israel and other potential regional targets. It denies seeking nuclear weapons.
In 2018, then-U.S. President Donald Trump withdrew from the nuclear deal and reimposed sanctions to force Tehran into talks on a broader agreement addressing its missiles and support for regional proxies.
Tehran has not bowed to the pressure. Here are some facts about its ballistic missile programme, which is supplemented by cruise missiles and drones.
According to the U.S. Office of the Director of National Intelligence, Iran is armed with the largest number of ballistic missiles in the region.
The Arms Control Association, a Washington, D.C.-based non-governmental organization says Iran's missile program is largely based on North Korean and Russian designs and has benefited from Chinese assistance.
The program, which contains about 1,000 short-and medium range ballistic missiles, is one of the largest deployed in the Middle East, says the association. Iran is currently focused on enhancing the accuracy of the medium range systems, it says.
The Arms Control Association says Iran's short-range and medium-range ballistic missiles include Shahab-1, with an estimated range of 300 km, the Zolfaghar (700 km); Shahab-3 (800-1,000 km), Emad-1, a missile under development (up to 2,000 km) and Sejiil, under development (1,500-2,500 km).
Iran also has cruise missiles such as Kh-55: an air-launched nuclear-capable weapon (up to 3,000 km), and the advanced anti-ship missile the Khalid Farzh, (about 300 km) capable of carrying a 1,000 kg warhead.
Saudi Arabia and the United States have said they believe Iran was behind a drone and missile attack on its prized oil facilities in 2019. Tehran denied the allegation.
Iran showed its prowess in March when it attacked Erbil in northern Iraq with a dozen ballistic missiles, an unprecedented assault on the capital of the autonomous Iraqi Kurdish region.
Iranian state media said Iran's Revolutionary Guards carried out the attack against what they called Israeli "strategic centers" in Erbil, suggesting it was revenge for recent Israeli air strikes that killed Iranian military personnel in Syria.
Yemen's Iran-aligned Houthi movement has also shown a growing mastery of missile technology.
The group said it fired a number of ballistic missiles at Abu Dhabi, capital of the United Arab Emirates, and had also fired several drones at Dubai, the regional business hub.
In one of the attacks, a base hosting the U.S. military in the UAE was thwarted by U.S.-built Patriot interceptors. The attack sent U.S. troops into bunkers. The United States accuses Iran of arming the Houthis, a charge Tehran denies.
The leader of Lebanon's Iran-backed Hezbollah group has said the group has the ability within Lebanon to convert thousands of rockets into precision missiles and to produce drones.
In February, Hassan Nsrallah said Hezbollah was able to transform standard rockets into precision missiles with the cooperation of "experts from the Islamic Republic of Iran".
Iran has transferred indigenous precision-guided missiles to Syria to support President Bashar al-Assad’s fight against insurgents over the last 11 years, according to Israeli and Western intelligence officials.
It has also moved some of its production capacity to underground compounds in Syria, where Assad’s military and other pro-Tehran forces have learned to build their own missiles, those same sources say.
Israeli air strikes have repeatedly attacked both suspected weapons transfers and sites where those factories and storage facilities are located.