Iran's supreme leader has responded by ruling out negotiations with the US over Tehran's ballistic missile and nuclear programmes and urging Iranians to resist pressure.

An Iranian Revolutionary Guard's speed boat fires a missile during a military exercise on July 28, 2020.
An Iranian Revolutionary Guard's speed boat fires a missile during a military exercise on July 28, 2020. (AP)

The US is expanding the scope of Iran metals sanctions, targeting 22 specific materials allegedly used in connection with its nuclear, military or ballistic missile programmes, promoting the republic to respond by doubling down on threats of continued weapons development.

Iran's Supreme Leader Ayatollah Ali Khamenei on Friday ruled out negotiations with the US over Tehran's ballistic missiles after Secretary of State Mike Pompeo announced a "major expansion" of the Iran metals-related sanctions administered by the State Department, allowing Washington to blacklist those who knowingly transfer the materials to Iran.

"Iran's nuclear, ballistic missile, and military programs pose a grave threat to international peace and security," Pompeo said in a statement on Thursday.

Pompeo also said he was firm in his determination that Iran's elite security force, the Islamic Revolutionary Guard Corps (IRGC), controls Iran's construction sector.

As a result, sanctions may still be imposed on those who knowingly transfer certain materials, including graphite or raw or semi-finished metals, to or from Iran to be used in connection with the Islamic Republic's construction sector, Pompeo said.

The materials he said he had determined are used in connection with Iran's nuclear, military or ballistic missile programmes included aluminium powder with purity above 98 percent.

Khamenei rejects talks

Khamenei urged Iranians to resist US pressure.

"America's brutal sanctions on Iran are aimed at collapsing our economy ... Their aim is to limit our influence in the region and to halt our missile and nuclear capabilities," Khamenei said in a speech broadcast live on television.

"Relying on national capabilities and cutting our dependence on oil exports will help us to resist America's pressure."

READ MORE: US imposes more sanctions on Iran after missile attacks in Iraq

Iran's missile programme

Reports from early June suggested that Iran Alumina Company's aluminium complex near the city of Jajarm is also home to a secret facility, set up by the IRGC, that has produced powder for use in Iran's missile programme.

Aluminium powder is a key ingredient in solid-fuel propellants used to launch missiles.

The United States has previously targeted Iran's metals sector with sanctions in an effort to slash Iranian revenues.

Tensions between Washington and Tehran have spiked since Trump unilaterally withdrew in 2018 from the Iran nuclear deal struck by his predecessor, Barack Obama, and began reimposing sanctions that had been eased under the accord.

READ MORE: Revisiting US 'maximum pressure' on Iran amid the coronavirus pandemic

Source: Reuters