US Vice President Joe Biden has said that the United States would take action against Iran if its recent long-range ballistic missile tests were carried out in defiance of an international deal reached last year over Iran's nuclear programme.

"I want to reiterate, as I know people still doubt, if in fact they break the (nuclear) deal, we will act," Biden said on Wednesday during a visit to Israel and the Palestinian territories.

Biden spoke after meeting Israeli Prime Minister Benjamin Netanyahu, who forcefully opposed the nuclear accord with Iran, his country's arch-foe.

Iranian leaders on Tuesday threatened to abandon the international agreement if it conflicts with Tehran's "national interests" - just hours after the missiles were launched, which violate UN Security Council resolutions.

“If our interests are not met under the nuclear deal, there will be no reason for us to continue,” Abbas Araqchi, Iran’s deputy foreign minister, warned during remarks delivered to a group of Iranian officials in Tehran.”

Iran also said it fired two more long-range ballistic missiles on Wednesday as it continued military tests in defiance of US sanctions and fresh warnings from Washington.

Coming just weeks after the implementation of Iran's historic nuclear deal with world powers, this week's multiple missile tests were described by Iran's powerful Revolutionary Guards as a show of force in the face of US pressure.

After similar tests on Tuesday, Washington warned it could raise the issue with the UN Security Council and take further action after US sanctions were imposed in connection with Iran's missile programme in January.

Ballistic missile tests have been seen as a way for Iran's military to demonstrate that the nuclear deal will have no impact on its plans, which it says are for domestic defence only.

The hard-fought deal, which saw international sanctions lifted in exchange for curbs on Iran's nuclear ambitions, did not extend to its missile programme.

General Amir Ali Hajizadeh, who heads the Iranian Revolutionary Guards' aerospace wing, said the longer-range missiles tested would be capable of hitting Israel, the region's sole if undeclared nuclear power.