Britain is to ship heavy machine guns and ammunition to Kurdish forces fighting Islamic State jihadists in Iraq, Defence Secretary Michael Fallon announced Tuesday.

The arms shipment, worth �1.6 million ($2.6 million, two million euros), will arrive in Iraq on Wednesday.

"The Kurdish forces remain significantly less well equipped than ISIL (Islamic State) and we are responding to help them defend themselves, protect citizens and push back ISIL advances," he said in a written statement to parliament.

"The initial gifting package... will consist of heavy machine guns and ammunition," he said.

British Prime Minister David Cameron said Monday that Britain would be directly supplying Kurdish troops as they battle the advances made by Islamic State across swathes of Iraq and neighbouring Syria.

Fallon said the shipment followed a request from the Iraqi government.

He said Britain was committed to assisting Iraq by "alleviating the humanitarian suffering of those Iraqis targeted by ISIL terrorists".

He also said London would promote an "inclusive, sovereign and democratic Iraq that can push back on ISIL advances and restore stability and security across the country".

Meanwhile Britain will also work with the international community "to tackle the broader threat that ISIL poses to the region and other countries around the world, including the UK", he said.

Fallon said the shipment would cost an estimated �475,000 to transport to Iraq's Kurdish region.