Vadim Ghirda, File, Associated Press
In this Sept. 1, 2013, file photo, a U.S. Air Force plane takes off from the Incirlik airbase, in southern Turkey. Turkey has agreed to let the U.S. military use the key air base near the border with Syria to launch airstrikes against the Islamic State, senior Obama administration officials said July 23, 2015, giving a boost to the U.S.-led coalition amid a surge of violence in Turkey blamed on IS-linked militants.

WASHINGTON — Turkey has agreed to let the U.S. military use a key air base near the border with Syria to launch airstrikes against the Islamic State, senior Obama administration officials said Thursday, giving a boost to the U.S.-led coalition amid a surge of violence in Turkey blamed on IS-linked militants.

The agreement, which President Barack Obama and Turkish President Recep Tayyip Erdogan discussed in a phone call Wednesday, follows months of U.S. appeals to Turkey and delicate negotiations over the use of Incirlik and other bases by the U.S.-led coalition — a sensitive topic in Turkey. American officials said access to the base in southern Turkey would allow the U.S. to move more swiftly and nimbly to attack IS targets.

Turkey has yet to publicly confirm the agreement, and the U.S. officials requested anonymity because they weren't authorized to comment publicly. The White House declined to confirm the agreement, citing operational security concerns, but noted that Obama and Erdogan had agreed to "deepen our cooperation" on the fight against IS in their phone call Wednesday.

"Turkey is a critical partner in degrading and defeating ISIL, and we appreciate the essential support Turkey provides to the international coalition across the many lines of effort," said Alistair Baskey, a spokesman for the White House's National Security Council, using an alternative acronym for the militant group.

Incirlik Air Base, located in southern Turkey across the border from the Syrian city of Aleppo, is a joint U.S.-Turkish base. The U.S. Air Force's 39th Air Base Wing is based there, and its proximity to IS strongholds in Syria makes it a strategically advantageous place from which to attack the militant group. Turkey shares a 1,250-kilometer (775-mile) border with Iraq and Syria.

Turkey's consent came as the country finds itself drawn further into the conflict by a series of deadly attacks and signs of increased Islamic State activity inside the country. On Thursday, IS militants fired from Syrian territory at a Turkish military outpost, killing one Turkish soldier and prompting Turkish retaliation that killed at least one IS militant. Earlier in the week, a suicide bombing blamed on IS militants killed 32 people in southeastern Turkey, near the Syrian border.

Turkish officials have raised concerns that the bombing was part of a campaign of retaliation for Turkey's recent crackdown on IS operations in the country. In the last six months, Turkish officials say, more than 500 people suspected of working with IS have been detained. An investigation of recruitment networks in Turkey netted 21 terrorism suspects this month.

Reach Josh Lederman on Twitter at http://twitter.com/joshledermanAP and Matthew Lee at http://twitter.com/apdiplowriter