"In the next months we will see an operational style aimed at removing the YPG (Kurdish People's Protection Units militia) and Daesh (Islamic State group) elements on the ground in Syria," Erdogan said in Istanbul.

He promised last week to start a Turkish-led operation before US President Donald Trump on Wednesday ordered 2,000 American ground forces to leave Syria.

Erdogan welcomed Trump's decision but said he remained "cautious" because of "past negative experiences", referring to Ankara's continued disappointment over the US administration's failure to stop providing military support to the YPG against IS.

In November last year, Turkish officials said Trump had promised not to supply weapons to the YPG militia, although the White House was not as explicit about its intentions.

American support to the YPG militia which spearheaded Washington's battles in Syria to eliminate jihadists has long been a source of tension between the NATO allies.

Turkey says the YPG is a "terrorist offshoot" of the outlawed Kurdistan Workers' Party (PKK), which has been waging an insurgency against the Turkish state since 1984.

The PKK is blacklisted as a terror group by Turkey, the US and the European Union.

Erdogan said on December 12 that Turkey would start an offensive in northern Syria in "the next few days" but on December 14, he spoke to Trump on the phone.

According to Turkish daily Hurriyet on Friday, Trump decided to pull out of Syria during that call with Erdogan and ordered his national security adviser John Bolton to "start the work" to prepare withdrawing troops.

The Turkish head of state on Friday said the US decision meant Turkey would "wait a little longer" before launching an operation which would involve Syrian rebels.

"Of course this is not an open-ended waiting period," he warned, adding that Turkey was working on plans to "neutralise Daesh elements" that still exist in Syria.

"Mr Trump told us during our conversation 'will you clean Daesh from here?' We have cleared them and after this, we will clear them. As long as you give us the support in terms of logistics. And have they (the US) started to withdraw? They have," he added.