The leader of Hezbollah, Naim Qassem, said on Monday that his group was concerned about confronting Washington's threat against Iran, particularly any threat against Supreme Leader Ayatollah Ali Khamenei.

Tensions between Iran and the United States have grown following a severe crackdown on protests across Iran in which thousands were killed in the past few weeks, which President Donald Trump said could lead to a U.S. response. Tehran said any attack on Khamenei would trigger a "holy war".

"We are concerned with what is happening and targeted by potential aggression. We are determined to defend ourselves. We will choose in due course how to act, whether to intervene or not... but we are not neutral," Qassem said in a televised address.

Hezbollah “considers the threat to Khamenei to be a threat to us, and we have full authority to take whatever measures we deem appropriate to confront it,” said Qassem.

The Hezbollah leader said mediators had told the group the U.S. and Israel were considering hitting it in case there was an attack on Iran, saying that a war on Iran could ignite the entire region this time.