President Donald Trump is considering adding Iran's Islamic Revolutionary Guard to the list of prohibited terrorist organizations as part of a wave of new executive orders.

The move against the Islamic republic's most powerful security institution would deal a further blow to relations with Tehran.

Trump has also been warned it could have implications on the fight against ISIS, because Iran is one of the countries opposing the terror group.

But members of his administration have been pushing for him to increase sanctions against the state since his first day in the White House.

The US already has restrictions on individuals and organizations linked to the IRGC.

Iran was also one of the seven Muslim-majority countries part of his immigrant travel ban.

US President Donald Trump, sitting in the Oval office along with National Security Adviser Michael Flynn (center) and chief strategist Steve Bannon (right), is considering designating the Iranian Revolutionary Guard Corps as a terrorist organization by an executive order

The Iranian Revolutionary Guard Corps is the most powerful security and political organization in Tehran and placing it on a terror list could impact the United States' fight against ISIS

The White House is also considering placing the Muslim Brotherhood on the terror organization list, although this decision may be delayed.

Naming Iran's single most powerful military and political institution as a terrorist group could inflame regional conflicts involving the country.

It would also complicate the US fight against ISIS in Iraq, where Shi'ite militias backed by Iran and advised by IRGC fighters are battling the Sunni jihadist group.

After tightening sanctions against Iran last week in response to a ballistic missile test, White House officials said the measures were an 'initial' step.

US Gulf allies have long favored a tougher US stance against Iran, whom they blame for regional interference.

Donald Trump is believed to be preparing a range of new executive orders in the near future

Trump is considering imposing a range of new sanctions on the Iranian regime

But officials said the process for issuing controversial orders has slowed in the wake of the political and legal uproar over Trump's order to ban entry to the United States from seven majority-Muslim countries, which is now the focus of a court battle.

The United States has already blacklisted dozens of entities and people for affiliations with the IRGC.

In 2007, the US Treasury designated the IRGC's Quds Force, its elite unit in charge of its operations abroad, 'for its support of terrorism', and has said it is Iran's 'primary arm for executing its policy of supporting terrorist and insurgent groups'.

A designation of the entire IRGC as a terrorist group would potentially have much broader implications, including for the 2015 nuclear deal negotiated between Iran and the United States and other major world powers.

The nuclear deal, which has been criticized by Republicans for giving Iran too much and not placing tight enough restrictions on the country, granted Iran relief from most Western sanctions in return for curbs on its nuclear program.

Reuters reported last week that the IRGC designation is among the proposals being considered as part of an Iran policy review in the Trump administration. The objective would be to dissuade foreign investment in Iran's economy, because of the IRGC's involvement in major sectors including transportation and oil. In many cases, that involvement is hidden behind layers of opaque ownership.

One senior official told Reuters: 'The new administration regards Iran as the clearest danger to US interests, and they've been looking for ways to turn up the heat.'

The official said that rather than tearing up the nuclear agreement, a step he said even Israel and Saudi Arabia oppose, the White House might turn instead toward punishing Iran for its support for Lebanese militant group Hezbollah, the Houthi rebels in Yemen, and some Shiite forces in Iraq.

But sanctioning the IRGC could backfire, this official warned. It could strengthen the hardliners and undercut more moderate leaders such as Iranian President Hassan Rouhani, and encourage Iranian-backed forces in Iraq and Syria to curtail any action against Islamic State in Syria and Iraq and perhaps even sponsor actions against US-backed or even American forces battling Islamic State in Iraq.

The Revolutionary Guards answer to Iranian Supreme Leader Ayatollah Ali Khamenei, whose power far surpasses that of Rouhani.

The official warned: 'The Iranians will not take any US action lying down. They may not act quickly or in the open, but there is a danger of an escalating conflict.'

Current US sanctions include penalties for foreign companies which knowingly conducting 'significant' transactions with the Revolutionary Guards, or other sanctioned Iranian entities.

However, many companies in which the Revolutionary Guards have an interest in or own are not blacklisted, and have been able to sign foreign deals.