ISTANBUL (Reuters) - Turkey is uneasy about U.S. plans to set up “observation posts” in Syria along parts of its border with Turkey, Turkish Defence Minister Hulusi Akar said on Saturday.

FILE PHOTO: Turkey's Defence Minister Hulusi Akar talks with U.S. Secretary of Defense Jim Mattis during a NATO defence ministers meeting at the Alliance headquarters in Brussels, Belgium, October 4, 2018. REUTERS/Francois Lenoir

Defense Secretary Jim Mattis said on Wednesday the United States was setting up the posts to help keep the focus on clearing the final Islamic State militant strongholds in Syria.

The United States has long complained that tension between Turkey and the Syrian Democratic Forces (SDF) - which includes the Syrian Kurdish YPG militia - has at times slowed progress on the fight against Islamic State.

Akar said he told U.S. Chief of Staff Joseph Dunford and other U.S. officials during a recent visit to Canada that setting up the posts would have a very negative impact on perceptions of the United States in Turkey.

“During our talks with both political and civilian interlocutors we repeatedly expressed our unease in various ways,” he said. “I think actions like this will make the complicated situation in the region even more complicated”.

Turkey is angry at U.S. support for the YPG, which it views as an extension of the Kurdistan Workers Party (PKK) waging a decades-long insurgency on Turkish soil. The PKK is designated a terrorist group by Turkey, the United States and the European Union.

“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.

“We expect our U.S. allies to immediately cut their ties with the terrorist YPG, who are not in the slightest bit different from the PKK,” Akar added.

Islamic State is still present in eastern Syria in a pocket east of the Euphrates River near the border with Iraq.

President Donald Trump’s administration hopes that the U.S.-backed fight against Islamic State in its last foothold in northeastern Syria will end within months. But a top U.S. diplomat recently said American forces will remain to ensure the “enduring defeat” of the militant group.