"It is not possible for the Israeli administration, which has trampled on the fundamental values ​​of our alliance, to continue its partnership relationship with NATO," Erdogan told a press conference in Washington, D.C. after the NATO leaders’ summit.
The defense alliance has 32 members, but it also maintains relations with many non-member countries and international organizations called NATO partners.
NATO leaders gathered for a three-day summit to mark the military alliance's 75th anniversary.
Erdogan said that during his talks on the sidelines of the summit, he drew attention to the ongoing Israeli "atrocities" in the occupied Palestinian territories, particularly in Gaza.
Israeli Prime Minister Benjamin Netanyahu's administration, "with its expansionist and reckless policies," endangers the security of not only its own citizens, but also the entire region, he said.
"Until a comprehensive, sustainable peace is established in Palestine, attempts at cooperation with Israel within NATO will not be approved by Türkiye," Erdogan stressed.
"It is important that responsible members of the international community join hands for a two-state solution between Israel and Palestine based on the 1967 borders,” he said.
"Likewise, despite all the pressure and intimidation attempts, we are very pleased that the number of countries recognizing Palestine is increasing," Erdogan said, demanding other countries also file a complaint against Israel at the International Court of Justice (ICJ).
Türkiye is ready to take any initiative, including guarantorship, first for the declaration of a cease-fire and then for the establishment of permanent peace in Gaza, he said.
"I hereby call on all our allies to increase their pressure on the Netanyahu administration to ensure a cease-fire and the uninterrupted delivery of humanitarian aid to the people of Gaza, who have been starving for nine months," Erdogan added.
Israel has pounded the Gaza Strip since a cross-border attack by the Palestinian group Hamas on Oct. 7, 2023. Besides killing more than 38,000 Palestinians since then, the Israeli military campaign has turned much of the enclave of 2.3 million people into ruins, leaving most civilians homeless and at risk of famine.
Israel is also accused of committing genocide in the besieged Palestinian enclave, and a case is continuing at the ICJ in The Hague.
'Crooked relationship' of NATO allies with terror outfits
Turning to the fight against terrorism, Erdogan said there is a need to strengthen cooperation between NATO allies in the fight against terrorism.
"It is not possible for us to accept the crooked relationship that some of our allies have established especially with the PYD/YPG, the extension of the terrorist organization PKK in Syria," he added.
Ankara expects solidarity from the allies in the fight against terrorism, one of the two major threats identified by NATO, Erdogan said, adding: "The law of alliance also requires this."
Erdogan called on the allies to abandon these "erroneous policies" that harm the unity and integrity of NATO.
Türkiye has long complained of the US working with the PKK and its offshoots on the pretext of fighting the Daesh/ISIS terror group. Turkish officials say using one terrorist group to fight another makes no sense.
Ankara has launched a trio of successful anti-terror operations since 2016 across its border in northern Syria to prevent the formation of a terror corridor and enable the peaceful settlement of residents: Euphrates Shield (2016), Olive Branch (2018) and Peace Spring (2019).
In its more than 35-year terror campaign against Türkiye, the PKK – listed as a terrorist organization by Türkiye, the US and European Union – has been responsible for the deaths of more than 40,000 people, including women, children and infants. The YPG/PYD is the PKK’s Syrian offshoot.

Erdogan reminded reporters that he extended an invitation to Syrian President Bashar al-Assad to either come to Türkiye, or have a meeting in a third country.

"I urged Mr. Al-Assad two weeks ago, saying: 'Either come to our country or let's hold this meeting in a third country.' I have also instructed my foreign minister to handle this matter. By having discussions with his counterparts, we hope to overcome this grievance, and initiate a new process," the Turkish president added.