Turkey’s President Recep Tayyip Erdogan has said Ankara remains committed to rooting out a Syrian Kurdish militia from northern Syria. “Like I always say, we’ll come down on them suddenly one night. And we must,” Turkish President Recep Tayyip Erdogan told reporters on his plane following his Saturday visit to Azerbaijan. Without giving a specific timescale, Mr Erdogan said that Turkey would launch a cross-border operation against the Syrian Kurdish People’s Protection Units, or YPG. It considers this a terrorist organisation linked to an outlawed Kurdish group that has led an insurgency against Turkey since 1984. That conflict with the Kurdistan Workers' Party, PKK, has killed tens of thousands of people. However, the YPG forms the backbone of US-led forces in the fight against ISIS in Syria. American support for the group has infuriated Ankara and remains a major issue in their relations. Turkey considers the PKK and the YPG to be one and the same. “All coalition forces, leading with the US, have provided these terror groups with a serious amount of weapons, vehicles, tools and ammunition — and they continue to do so," Mr Erdogan said. "The US has given them thousands of trucks.” He warned that Turkey would not need anyone’s permission to fight terror. “If the US is not fulfilling its duty in combating terror, what will we do? We will take care of it ourselves,” he said. Ankara has launched four cross-border operations into Syria since 2016. In 2019, an incursion into north-east Syria against the YPG drew widespread international condemnation, prompting Finland, Sweden and others to restrict arms sales to Turkey. Now Turkey is blocking the two Nordic countries' historic bid to join Nato because of the weapons ban and their alleged support for the Kurdish groups. Turkey has stepped up military operations against the PKK in northern Iraq where they are based. The PKK is considered a terror group by Turkey, the US and the European Union. “Just as we are conducting operations in northern Iraq against the PKK and PKK's offspring, the same situation applies even more to Syria and is much more important,” Mr Erdogan said.