Heavily armed Kurdish peshmerga fighters set off from their base in northern Iraq Tuesday to support militia forces defending the Syrian border town of Kobane from the Islamic State group.

Military trucks loaded with weapons departed from the base northeast of the Iraqi Kurdish regional capital Arbil bound for the besieged town on the Turkish frontier, an AFP correspondent said.

More than three dozen vehicles carrying 80 fighters, machineguns and artillery were to travel overland to Kobane, crossing the border into Turkey on Tuesday, a Kurdish officer said.

The convoy included two towed artillery pieces and a number of covered trucks, some of them carrying rocket launchers.

Another 72 peshmerga fighters were to fly to Turkey early on Wednesday, the officer said.

Kobane's Kurdish defenders have been waiting for days for the arrival of the peshmerga fighters, after Turkey last week said it would allow them to traverse its territory to enter the town.

Turkish Foreign Minister Mevlut Cavusoglu said there would no problem for the peshmerga to cross into Kobane, dismissing reports of delays imposed by Ankara.

"There is now no political problem. There is no problem in the way of them crossing. They can cross at any moment," Cavusoglu was quoted as saying by the official Anatolia news agency.

Local Kurdish militia have been holding out against an IS offensive for weeks and the town has become an important symbol in the international battle against IS.

The fighting continued on Tuesday, an AFP reporter at Mursitpinar across the border in Turkey said, with black smoke rising over the town as the jihadists set fire to tyres in a bid to prevent air strikes.

- Turkey urges 'integrated strategy' -

The US-led coalition waging an air campaign against IS has pounded jihadist positions in Kobane in recent days in a bid to prevent the town's fall.

The US military said in a statement that four more air strikes had hit IS near Kobane on Monday and Tuesday, along with nine raids on the group in Iraq.

The extremists seized control of large parts of Syria and Iraq earlier this year, declaring an Islamic "caliphate" and committing widespread atrocities.

The group's growing power and influence has raised global concerns but Washington and its allies have so far refused to commit to deploying ground forces against the jihadists.

Turkish Prime Minister Ahmet Davutoglu called Tuesday for an "integrated strategy" in the fight against IS and repeated calls to support the anti-Damascus Free Syrian Army.

Turkey has urged the global community to combine the fight against IS with wider support for the uprising against President Bashar al-Assad's regime.

Davutoglu said he wanted the FSA to control Kobane if the jihadists are defeated, not the forces of separatist Kurds or Assad.

The United States should "equip and train the Free Syrian Army so that if ISIS leaves, the regime should not come," he said, using another name for IS.

"If ISIS leaves the PKK terrorists should not come, if ISIS is eliminated, the brutal massacres should not continue," he added.

Turkey is fearful that Kobane could be taken over by Kurds allied to the Kurdistan Workers' Party (PKK) which has waged a three-decade insurgency for self rule and is regarded as a terrorist group by Turkey, the United States and most of Europe.

The uprising against Assad has raged for more than three-and-a-half years, leaving more than 180,000 dead and forcing some three million Syrians to flee the country.

- Call to help refugee hosts -

The United Nations on Tuesday issued a call for more funding to help countries such as Lebanon and Jordan hosting the refugees, warning that the world was facing its "most dramatic humanitarian crisis" in the conflict.

UN High Commissioner for Refugees Antonio Guterres told an international conference in Berlin that the impact of the refugee crisis on Syria's neighbours had been "enormous".

"Economics, public services, the social fabric of communities and the welfare of families are all affected, not to mention the security impact of the Syrian conflict in the whole region," he told the gathering.

He called for "much stronger financial support" for host countries, as ministers from Lebanon, Jordan, Turkey, Egypt and Iraq outlined their struggles.

Lebanese Prime Minister Tammam Salam said other countries needed to "share its burden" in hosting refugees, while Jordan's Foreign Minister Nasser Judeh said there was a danger of "host community fatigue" without urgent help.