A U.S. armed drone bombed a target in Islamic State-controlled northern Syria on Wednesday, in the first such air strike by a U.S. aircraft after taking off from Turkish territory, a Turkish official told AFP.

"A U.S. drone today carried out one air strike in Syria near Raqa," said the official, referring to the town in northern Syria the IS group sees as its capital. 

Ankara on Wednesday appointed a new army chief as Turkey wages a dual offensive against Kurdish militants and Islamic State (IS) jihadists. 

Land Forces commander Hulusi Akar, 63, takes over as chief of staff from retiring General Necdet Ozel as part of a major shake-up of the army's top brass. 

The co-chair of Turkey's main Kurdish party is to make an unscheduled trip to Brussels on Wednesday, his party said, amid reports he will meet representatives of the outlawed Kurdistan Workers' Party (PKK).

Selahattin Demirtas of the Peoples' Democratic Party (HDP) postponed his scheduled program in Ankara Wednesday, a party official told AFP, saying: "He is due to travel to Brussels."

Turkey on Wednesday announced that it was ready to begin a "comprehensive" fight against Islamic State (IS) jihadists in Syria alongside the United States, after a months of staying on the sidelines of the U.S.-led coalition.

Ankara, long criticized for failing to stop the flow of jihadists to-and-fro across its border with Syria, has so far concentrated an almost two-week "anti-terror" campaign on the bombing of Kurdish militants.

Qatar has broken ranks with the Arab League to give close ally Turkey its full support for air strikes in northern Iraq, according to an official foreign ministry statement.

On Tuesday, the Arab League condemned Turkey's actions and called on Ankara to recognize the sovereignty of Iraq.

The end to a ceasefire with Kurdish rebels and political uncertainty after inconclusive June elections are compounding already mounting problems for Turkey's stuttering economy, analysts say.

The resumption of regular attacks by Kurdistan Workers' Party (PKK) rebels in the southeast of the country as Turkish jets bomb their positions in northern Iraq has brought back memories of the 1990s when the country was often in economic, political and security chaos.

Turkish prosecutors on Tuesday asked for jail sentences of up to seven and a half years for 18 journalists on charges of making propaganda for a terrorist group after publishing a picture from an Istanbul hostage siege.

The journalists charged from nine different newspapers included the editor-in-chief of the pro-opposition Cumhuriyet daily Can Dundar who has repeatedly locked horns with President Recep Tayyip Erdogan.

Turkey's air strikes in Iraqi Kurdistan have increased the pressure on regional president Massud Barzani, who is a key player in the U.S.-led anti-jihadist war but faces an uncertain political future.

Barzani, the 68-year-old leader of the Kurdistan Democratic Party (KDP), has been at the helm of Iraq's autonomous Kurdish region for 10 years.

The EU on Tuesday urged Turkey to make a "proportionate" response to "terrorism" in order not to endanger a faltering peace process with Kurdish rebels.

EU enlargement commissioner Johannes Hahn told Turkish EU Minister Volkan Bozkir that Ankara has "the right to react to any form of terrorism," according to an EU statement.

Two soldiers were killed in southeastern Turkey on Tuesday when a mine exploded in the latest attack on security forces blamed on the outlawed Kurdistan Workers' Party (PKK), the army said.

Kurdish militants detonated a remote-controlled mine as a military convoy passed by in the Arakoy region of Sirnak province bordering Iraq and Syria, it said.