Islamic State have released what it claims is a recording of their leader, Abu Bakr al-Baghdadi.
The reclusive leader of IS, who has only appeared in public once, also vowed to continue fighting and lavished praise on his jihadis for their bravery in the battlefield - despite the militants’ loss of the northern Iraqi city of Mosul in July.
The recording was released by the IS-run al-Furqan outlet, which has in the past released messages from Baghdadi and other top figures of the extremist group.
Baghdadi spoke of what he called the United States’ waning global power. Citing examples of America’s perceived weakness, he referred to Russia’s annexation of Crimea and "North Korea’s nuclear threat against America and Japan".
Al-Baghdad’s reference to North Korea’s tussle with Washington and Tokyo over Pyongyang’s nuclear and long-range missile programmes suggests his message was recently recorded, perhaps in the past month or two.
The voice in the 46-minute audio sounded much like previous recordings of Baghdadi. His last previous purported message was released in November, also in an audio recording.
"You soldiers of the caliphate, heroes of Islam and carriers of banners: light a fire against your enemies," said Baghdadi, a shadowy cleric who has been surrounded by controversy since the Sunni terror group emerged from al Qaida in Iraq.
Russian officials said in June there was a "high probability" that Baghdadi had died in a Russian air strike on the outskirts of the Syrian city of Raqqa, the group’s de facto capital. US officials later said they believed he was still alive.
Baghdadi’s whereabouts are unknown but he is believed to be in IS’s dwindling territory in eastern Syria.
The IS-held cities of Raqqa and Deir el-Zour are under siege and probably too dangerous for him to hide in.
Some IS leadership is believed to have gone to the nearby town of Mayadeen, and the group still holds a stretch of the Euphrates River from Deir el-Zour to the Iraqi border, as well as remote desert areas along the border.
"You soldiers of Islam, supporters of the caliphate everywhere, step up your attacks and include the media centres of the infidels and the headquarters of their ideological war among your targets," he said in the recording, apparently alluding to Western news outlets and research centres.
"Don’t you dare allow the Crusaders and the apostates to enjoy a good and comfortable life at home while your brothers are enduring killings, shelling and destruction," added Baghdadi, who reminded his followers of the rewards of martyrdom, including "72 wives" from among the maidens of paradise.
He also lauded his fighters for what he called their valiant fight against US-backed Iraqi forces that wrested control of Mosul, Iraq’s second largest city, from IS after nearly nine months of fighting.
"In Mosul, they defiantly stood firm on a land ruled by God’s laws against the infidels and nations of the cross ... only leaving it over their skulls and dead bodies after nearly a year of fighting," he said. "The sons of Islam will willingly continue to sacrifice their blood and bodies for the sake of their creator," he defiantly declared.
In the recording, he also consoled IS fighters over the number of major military setbacks suffered in recent months in both Iraq and Syria, but also made a passionate plea for them to rise up and never surrender.
"You Sunnis of Iraq, Syria, Yemen and everywhere ... get out of your beds and shake off oppression ... return to your faith and restore your glory and eminence," he said.