Jerusalem - US Vice President Joe Biden said on Wednesday that the United States would take action against Iran if long-range ballistic missile tests Tehran said it carried out were confirmed.

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

"All their conventional activity outside the deal, which is still beyond the deal, we will and are attempting to act wherever we can find it." Iran 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.

Moreover, Saudi Arabia and other Gulf monarchies could turn a page and build strong relations with Iran if it respects them and stops “meddling” in their affairs, Foreign Minister Adel al-Jubeir said Wednesday.

“If Iran changes its way and its policies, nothing would prevent turning a page and building the best relationship based on good neighbourliness, with no meddling in the affairs of others,” he told reporters in Riyadh.

 “There is no need for mediation” in such a case, said Jubeir, whose country severed all links with the Islamic republic in January after crowds attacked the kingdom’s diplomatic missions in Iran. Jubeir said relations with Tehran had deteriorated “due to the sectarian policies” followed by Shiite-dominated Iran and “its support for terrorism and implanting of terrorist cells in the countries of the region”.

“Iran is a neighbouring Muslim country that has a great civilisation and a friendly people, but the policies followed that the revolution of (Ayatollah Ruhollah) Khomeini have been aggressive,” he said.

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

Israel's regional military clout should be preserved in terms of the quantity as well as the quality of its weaponry, US Vice President Joe Biden said on Wednesday in a nod to Israeli requests in defence aid negotiations with Washington.

Current US military grants to Israel, worth about $3 billion annually, expire in 2018. The allies want to agree on an extension before US President Barack Obama leaves office in January 2017 but have differed over the proposed sums.

Israel, which last year requested $5 billion in future annual aid but whose officials have since set their sights on $4 billion to $4.5 billion, says it needs to expand its military, rather than just upgrade technologies, given spiralling arms procurement it anticipates by arch-foe Iran and Arab states.

US officials have given lower target figures of around $3.7 billion. The dispute prompted Israeli officials to hint last month that Prime Minister Benjamin Netanyahu, in hope of better terms, may await Obama's successor to conclude the deal.

"We're committed to making sure that Israel can defend itself against all serious threats, maintain its qualitative edge with a quantity sufficient to maintain that," Biden told reporters after meeting Netanyahu during a visit to Israel.

Israel's "very, very tough neighbourhood, a tough and changing neighbourhood" necessitated such assistance, Biden said, adding that Obama had "done more to help bolster Israel's security than any other administration in history".

He did not explicitly mention the accord on future US defence aid, known as the Memorandum of Understanding (MOU).

US congressional staffers said Biden would discuss the MOU during his Israel visit, describing the vice president as the only possible principal from the administration who could finish off a deal given Netanyahu's troubled ties with Obama.

Israeli Defence Minister Moshe Yaalon travels to Washington for talks next week with US counterpart Ashton Carter. Yaalon aides said he would try to make progress on the MOU.

Interviewed by Israel Radio on Wednesday, Yaalon did not refer to the MOU but said: "There are areas in which we know how to insist on our security interests, even when our great friend (the United States) makes offers that do not suit us."