Turkey's reluctance to intervene in the battle against ISIL, which has seized large areas of neighboring Syria and Iraq, has led to growing frustration in the United States.

Ankara views the Syrian Kurds with deep suspicion because of their ties to the Kurdistan Workers’ Party (PKK), a group that has waged a decades-long insurgency in Turkey and that Ankara and Washington regard as a terrorist organization.

Turkey has stationed tanks on hills overlooking Kobane but has refused to help the Kurdish fighters on the ground without striking a broader deal with its NATO allies on intervening in the Syrian civil war, saying action should also be taken against Syrian President Bashar al-Assad.

Ankara's announcement came after the United States on Sunday airdropped arms for the first time to help those attempting to resist ISIL attacks.

Turkey confirmed Monday that it is helping Iraqi Kurdish forces cross its borders to bolster the ranks of fellow Kurds defending the besieged Syrian border town of Kobane, where weeks of fighting have failed to permanently repel advancing members of the Islamic State in Iraq and the Levant (ISIL).

Washington said "small arms" were supplied by Iraqi Kurdish authorities and were dropped near Kobane, which came under ISIL attack in September and is now besieged from the east, west and south. It is bordered to the north by Turkey.

"It would be irresponsible of us, as well morally very difficult , to turn your back on a community fighting ISIL as hard as it is at this particular moment," he added.

"Let me say very respectfully to our allies the Turks that we understand fully the fundamentals of their opposition and ours to any kind of terrorist group and particularly obviously the challenges they face with respect the PKK," he said. "But we have undertaken a coalition effort to degrade and destroy ISIL, and ISIL is presenting itself in major numbers in this place called Kobane."

Speaking in the Indonesian capital of Jakarta, Kerry told reporters that the administration understood Turkey's concerns about supplying the Syrian Kurds.

U.S. Secretary of State John Kerry said Monday the White House decided to airdrop weapons and ammunitions to "valiant" Kurds fighting ISIL extremists in Kobane because it would be "irresponsible" and "morally very difficult" not to support them.

However, Foreign Minister Mevlut Cavusoglu told a news conference that Turkey was facilitating the passage of Iraqi Kurdish security forces, or peshmerga, which fought ISIL when the insurgents attacked the Kurds' autonomous region in Iraq over the summer. Cavusoglu gave no further details.

The policy has provoked lethal riots in southeastern Turkey by Kurds furious over Ankara's refusal to help Kobane or at least open a land corridor for volunteer fighters and reinforcements to go there.

Supporting ‘terrorists’

Redur Xelil, a spokesman for the main Syrian Kurdish armed group, the YPG, told Reuters the "large quantity" of weapons, ammunition and medical supplies dropped overnight would have a "positive impact" on the battle and the morale of fighters who have been outgunned by ISIL.

But he added that the shipment would "not be enough to decide the battle."

"We do not think the battle of Kobane will end that quickly. The forces of [ISIL] are still heavily present and determined to occupy Kobane." Xelil declined to give more details on the shipment.

The U.S. began carrying out airstrikes against ISIL targets in Iraq in August and about a month later started bombing the group in neighboring Syria.

But Turkey’s decision to allow Iraqi Kurds to bolster the ranks of Kurdish fighters in the conflict marks an escalation in the U.S.-led effort to help local forces beat back the radical Sunni insurgent group in Syria. It points to the growing coordination between the U.S. military and a Syrian Kurdish group that the West had kept at arm's length partly because of Turkey's concerns.

U.S. President Barack Obama gave advance notice to Turkish President Recep Tayyip Erdogan of U.S. plans to deliver arms to the Syrian Kurds.

The Kurds say the U.S. military has been coordinating the airstrikes with them, helping make them more effective.

In a brief statement, U.S. Central Command said 135 airstrikes were carried out near Kobane in recent days, killing hundreds of extremists. Combined with continued resistance against ISIL on the ground, they appear to have slowed the group's advances into the town. But Central Command added that the security situation in Kobane “remains fragile.”

Meanwhile, Ankara said Obama and Erdogan have discussed Syria, including measures that could be taken to stop ISIL’s advances in Kobane and elsewhere.

In comments published by Turkish media on Monday, Erdogan equated the main Syrian Kurdish political group, the PYD, with the PKK, describing both as terrorist organizations.

"It will be very wrong for America, with whom we are allied and who we are together with in NATO, to expect us to say yes [to supporting the PYD] after openly announcing such support for a terrorist organization," Erdogan said.

Al Jazeera and wire services