The U.S. is backing Turkey's two-pronged air offensive and artillery strikes against Islamic State militants in Syria and Kurdish rebel targets in Iraq.
The move follows a week in which violence in Turkey was blamed on both organizations - who are themselves staunch rivals.
A White House spokesman said Sunday Ankara was within its rights to "take action related to terrorist targets," including when it struck a Kurdish Workers' Party (PKK) town overnight Friday in northern Iraq, marking the first offensive against the outlawed Kurdish group there since a peace accord was announced in 2013.
Meantime, NATO said it will meet on Tuesday to discuss security at Turkey's request.
The PKK said its peace deal with Ankara had lost all meaning after the airstrikes.
The Turkish army is blaming Kurdish rebels for a car bombing late Saturday that killed two soldiers in the Kurdish-dominated southeast amid escalating tensions between the government and the separatist group.
The Kurds are separately fighting Islamic State militants encroaching on their cities in Iraq and Syria, and has accused the Turkish government of being complicit in support of IS fighters.
Turkey joined military efforts against IS in recent days, in a long-awaited move by Western and regional coalition partners who have been bombing the extremist group since August.
On Twitter, a top U.S. official for the country's anti-Islamic State efforts dismissed a relationship between the offensives against the PKK and Islamic State rebels, known also as ISIL.
"There is no connection between these airstrikes against PKK and recent understandings to intensify U.S.-Turkey cooperation against ISIL," Brett McGurk wrote.
Washington has pushed for broader regional support against Islamic State. White House spokesman Ben Rhodes, on an official visit to Kenya with President Barack Obama, told a news conference in Nairobi on Sunday that Ankara's decision to join militarily can lead towards an "even broader and more effective effort to degrade the ISIL safe haven across northern Syria and northern Iraq."
"Turkey can play an important role in those efforts," he added.
The Pentagon reported Sunday the U.S.-led coalition continued its daily airstrikes against Islamic State, with 13 bombings in Syria focused on the northern area of Hasakah and the border city of Kobani. Another 20 strikes targeted IS positions around Iraq.
Members of Turkey's parliament are expected to gather July 29 for an extraordinary session, according to the English-language Hurriyet Daily News.
Prime Minister Ahmet Davutoglu said Saturday Turkey's security operations will continue as long as necessary. "These operations are not one-point operations and will continue as long as there is a threat against Turkey," Mr. Davutoglu said. "No one should doubt our determination. We will not allow Turkey to be turned into a lawless country."
In a phone call with the Turkish leader on Sunday, German Chancellor Angela Merkel urged the NATO partner to use "proportionality" in responding to its internal conflict.
VOA White House correspondent Aru Pande contributed to this report from Nairobi.