On Friday 27 January, President Trump signed an executive order temporarily blocking travel for immigrants from seven “terror prone” Muslim-majority countries.

The ban is expected to last at least four months and will not apply to religious minorities 'fleeing Muslim persecution' from those countries - for example, Christians.

Three of these countries are already on the US State Sponsors of Terrorism list, which mandates strict economic sanctions affecting economic assistance, trade and the protection of international law.

1. Iran

Has been on the list since 1984. It has sponsored terror groups in Gaza and deployed its Islamic Revolutionary Guard Corps to promote its interests in the wider Middle East. The IRGC has provided advisory and combat assistance to the Assad regime in Syria.

2. Sudan

Has been on the list since 1993. The Sudanese government has cooperated with US anti-terror initiatives, but the country harbours a strong al-Qaeda network, Hezbollah operatives and the Lord’s Resistance Army.

3. Syria

Has been a designated State Sponsor of Terrorism since 1979. A staunch supporter of Iran’s efforts to rearm Hezbollah, the government also allowed Islamist fighters to travel through the country en route to conflicts in Iraq. These fighters were the genesis of ISIL, which is now headquartered in Syria.

Two of the other countries have historically been on the terrorism list:

4. Iraq

On the list since 1979, briefly removed during the Iran-Iraq War then re-added with the invasion of Kuwait in 1990. George W Bush removed the country from the official terror list in 2004, but Iraq is now a significant stronghold for ISIL.

5. Libya

On the list since 1979, but officially removed in 2006 after diplomatic efforts by then-leader Muammar Gaddafi. Following the Libyan government’s collapse into civil war and until late 2016, ISIL held the port city of Sirte with the aim of using it as a maritime base.

6. Somalia

Terrorist group al-Shabab is affiliated with al-Qaeda. In 2016, President Barack Obama added the group to a “perpetrators of 9/11” war authorisation, intensifying US airstrikes against the organisation, in support of the Somali government.

7. Yemen

Both sides of the ongoing Yemeni civil war have clashed with al-Qaeda’s branch in Yemen. Notably, the Charlie Hebdo attackers claimed allegiance to this organisation.