Turkish President Recep Tayyip Erdogan lashed out Tuesday against the U.S. troop presence in eastern Syria, charging that American plans to set up observation posts along the Turkish-Syrian border are meant to aid terrorist elements in the U.S.-backed Syrian Democratic Forces (SDF).

Without naming the U.S., a NATO ally, Erdogan said, "Those who say they are countering [ISIS] in Syria are in fact allowing a small group of terrorists to exist in the country to justify their presence in the war-torn country," according to Turkey's Hurriyet newspaper.

Erdogan was referring to the YPG (People's Protection Units), the Kurdish force within the SDF that has been instrumental in driving the Islamic State from Raqqa and now is pressing the last pocket of ISIS fighters in Syria near the Iraqi border.

Turkey considers the YPG to be an ally of the PKK (Kurdistan Workers Party), which has been labeled a terrorist group by it and the U.S.

Erdogan charged that the U.S. is falsely claiming to be fighting terror through the presence of its estimated 2,000 troops in Syria, saying it is actually showing a preference to "live and breathe with the terrorists" by backing the SDF and its YPG contingents.

"The only target of this terror organization [YPG], which is the Syrian branch of the PKK, is our country," he said. "It's not possible for us to remain idle against this threat."

Erdogan spoke ahead of a meeting of his National Security Council to consider regional issues, including the plan announced last week by Defense Secretary Jim Mattis to set up observation posts manned by U.S. troops in northern Syria.

In making the announcement to Pentagon reporters, Mattis rejected the charge that the YPG is allied with the PKK.

The Turks "don't like our relationship" with the YPG, he said. "I understand where they're coming from. But we do not say that YPG is the same as PKK."

Mattis said the observation posts will give early warning to Turkey of any threats headed north and also prevent clashes between the Turkish military and the YPG.

A U.S. military spokesman said Tuesday that U.S. troops are present along the Turkey-Syria border but are still in the process of selecting locations for the observation posts.

"Turkey was fully briefed" on the observation posts as the planning proceeded, Army Col. Sean Ryan, a spokesman for Combined Joint Task Force-Operation Inherent Resolve, said in a video briefing to the Pentagon from Baghdad.

Ryan said the posts are "committed to security in the northern Syria region. … It takes into account Turkey's security as well."

However, Turkish Defense Minister Hulusi Akar said Saturday that the observation posts will aggravate the security situation in the region, Turkey's state Anadolu news agency reported.

"I think actions like this will make the complicated situation in the region even more complicated," Akar said, adding that the Turkish military will not hesitate to launch cross-border attacks against perceived threats.

"Nobody should doubt that the Turkish armed forces and the Republic of Turkey will take the necessary steps against all kinds of risks and threats from across its borders," he said.

On other issues, Ryan confirmed that a major counterattack by ISIS in Syria last weekend killed at least 80 troops from the U.S.-backed SDF, showing the resilience of the terrorist organization despite an 11-month siege of its last refuge in Syria near the town of Al-Tanf on the Iraqi border.

Ryan said the SDF had regained territory lost in the counterattack and resumed offensives against Al-Tanf. "We should remain patient as fighting continues to be intense," he added.

-- Richard Sisk can be reached at Richard.Sisk@Military.com.