The People's Protection Units (YPG) is "the Syrian militia" of the PKK terrorist group, U.S. Director of National Intelligence Dan Coats said in a report published Tuesday.

The annual report, "Worldwide Threat Assessment of the U.S. Intelligence Community," defines threats to U.S. national security in 2018, according to the country's intelligence community.

Assessing the situation in Syria, Coats acknowledged the link between the YPG and PKK, which is designated as a terrorist organization by Turkey, the U.S. and EU.

He went on to say that the YPG "probably will seek some form of autonomy [in northern Syria] but will face resistance from Russia, Iran, and Turkey."

This confirms Ankara's concerns that the PKK's Syrian affiliate Democratic Union Party (PYD) and its YPG militia seek to create a "terror state" along Turkey's 822-kilometer border with Syria.

However, this is not the first time the U.S. has confirmed this link.

Despite the previous U.S. administration's insistence on recognizing no direct link between the PKK and the PYD and its YPG, former U.S. Secretary of Defense Ashton Carter had confirmed the link between the groups while testifying before a Senate panel in April 2016.

After acknowledging the link between the PKK and PYD, Carter confirmed that the PKK is a designated terrorist group by the U.S., Turkey and the EU.

The CIA has also officially confirmed that its sees the PYD, whose former co-chair is Salih Muslim, as the Syrian affiliate of the PKK. Under its "The World Factbook" section and Syria subcategory, the agency listed the Syria-based PYD as a PKK branch under foreign-based terrorist groups. The page was last updated on Jan. 23, 2018.

The fact that the CIA connects the YPG and PYD with the PKK, besides confirming the U.S.'s open support for a terrorist group, is also legally problematic for the U.S., as it is against U.S. law, as 18 U.S. Code § 2339B on providing material support to designated foreign terrorist organizations clearly states: "Whoever knowingly provides material support or resources to a foreign terrorist organization, or attempts or conspires to do so, shall be fined under this title or imprisoned not more than 20 years, or both, and, if the death of any person results, shall be imprisoned for any term of years or for life."

Similarly, section 2339A says: "Whoever provides material support or resources or conceals or disguises the nature, location, source, or ownership of material support or resources knowing that such support will be used to commit one of the offenses specified in the statute (destruction of aircraft, biological or chemical weapons, arson, causing injury or death, acts of terrorism transcending national boundaries to list a few) will be subject to prosecution."

A Tactical Action Report (TAR) prepared by the U.S. Army Training and Doctrine Command (TRADOC) had also confirmed the affiliation between the PKK, PYD and YPG.

Previously, Muslim also implicitly accepted that there were hundreds of PKK militants in the ranks of the YPG.

The U.S.'s continuous support for the Syrian Democratic Forces (SDF), which is dominated by YPG terrorists, has long been a cause of tension between Ankara and Washington.

Coats also said the Syrian conflict "has decisively shifted in the [Syrian] regime's favor, enabling Russia and Iran to further entrench themselves inside the country. Syria is likely to experience episodic conflict through 2018, even as [the regime] recaptures most of the urban terrain and the overall level of violence decreases."

He added that the Syrian opposition is probably no longer capable of overthrowing Bashar Assad or overcoming the growing military disadvantage.

U.S. Secretary of State Rex Tillerson is expected to arrive in Turkey on Thursday to discuss the escalating PKK crisis between the two NATO allies amid Turkey's Operation Olive Branch in northwestern Syria's Afrin which aims to clear the region from YPG and Daesh terrorists.