ISIS have called for attacks against the United States and Europe to take place during the holy month of Ramadan.

In a new audio message posted online, the group's spokesman Abu Mohamed al-Adnani attempted to keep morale high among supporters following recent defeats in key city strongholds across Iraq and Syria.

He also called for attacks during Ramadan, which starts in early June this year, an appeal he made at the same time last year when urging supporters to seek 'martyrdom'.

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Abu Mohammed al-Adnani, earmarked as the group's next leader, was reported as having lost 'a large amount of blood' after being hit in the town of Barwanah, in the Anbar province, yesterday

The recording - titled 'That They Live By Proof' - was directed at both Jews and Christians, and spoke of the terror network's plans to take over the world

Adnani said: 'Ramadan, the month of conquest and jihad. Get prepared, be ready...to make it a month of calamity everywhere for the non-believers...especially for the fighters and supporters of the caliphate in Europe and America.

'The smallest action you do in their heartland is better and more enduring to us than what you would if you were with us. If one of you hoped to reach the Islamic State, we wish we were in your place to punish the Crusaders day and night.

'Will we be defeated if we lose Mosul, or Sirte, or Raqa, or all the cities, and go back to how we were before?

'No. Defeat is only losing the desire and the will to fight.'

The 31-minute recording - posted late on Saturday night - was Adnani's first speech since October.

It made no reference to the downing of EgyptAir flight MS804.

Al-Adnani is considered the terror network's most prominent public figure in Iraq, having made several audio messages in the past.

He is held in the same bracket of notoriety as Abu Bakr al-Baghdadi, the caliph of the Islamic State in Iraq and Syria, and has been suggested as the jihadists' next leader should Baghdadi lose his position.

The 31-minute recording - posted late on Saturday night - was Adnani's first speech since October. It made no reference to the downing of EgyptAir flight MS804 (pictured)

He was held in custody - believed to have been at the American detention facility, Camp Bucca - after being captured by US troops in 2005, remaining a prisoner until 2010.

A £2.5million bounty was issued in May 2014 for information leading to the Syrian born extremist, referring to his 'repeated calls for attacks against Westerns'.

In June of that year, he declared a 'caliphate' for parts of Syria and Iraq indicating ISIS' aim of not just being a terrorist group, but a governing body.

His latest speech came 24 hours after flyers apparently dropped by the coalition on Raqa city in northern Syria urged residents to leave the city, perhaps ahead of an offensive by anti-IS forces to recapture it.

'It would appear IS is more clearly acknowledging its limitations in holding territory' while stressing the 'idea of living on despite losses,' wrote jihadism expert Aymenn al-Tamimi in reaction to Adnani's recording.