The US has promised Turkey that it will track and take steps to defund the Kurdish militia PKK in an attempt to reassure Recep Tayyep Erdogan's government, after relations between Washington and Ankara came close to fracturing over Syria.

The Trump administration has decided to provide heavy weapons to some Kurdish groups fighting Isis, a move which has led to severe and prolonged criticism from Ankara. But Turkish Prime Minister Binali Yildirim, speaking in London on Friday said that the US has stressed it continues to regard the PKK as terrorists and will pursue the organisation’s money trail.

According to Mr Yildirim, the US has also promised that Kurdish forces that may enter Raqqa (Isis's de facto capital in Syria), as part of an American-backed offensive, will not be allowed to stay in the city.

Mr Yildirim said he had been given the commitment about pursuing the PKK by General James Mattis, US Defence Secretary, during a counter-terrorism conference in London. “He was very clear that the US regards the PKK as a terrorist organisation and will start tackling the money of the PKK,” said the Prime Minister.

“We have also been told by the US that Kurdish groups will not stay in Raqqa; the demographic of the region will not change.”

Mr Yildirim said that he understood Britain's position to be the same: that the UK views the PKK as a terrorist group. But he castigated the European Union for what he claimed was its backing of the Kurdish organisation. “The PKK deals in drugs: it peddles heroin and cocaine to the European youth –that’s how they make money,” he said.

“Yet the European Union still supports this organisation. If they are doing this to punish Turkey, they should think about the health of their future generations.”

Donald Trump will meet President Erdogan next week. Meanwhile, Turkey continues to protest the supplying of advanced arms to the Kurdish YPG (who the Americans consider the most effective of their allies against Isis), and the SDF, which has Arabs in its ranks but is led by Kurds.

The Turkish government holds that both the groups are tied to the PKK and arming them would have a “negative effect both for Turkey and the US”.

Mr Yildirim charged today: “The PKK take different initials like YPG and SDF. But they are all the same. We will defend ourselves from them in Turkey. When they use Iraq and Syria to attack us, we will go against them and deal with them in Iraq and Syria as well.”

Mr Yildirim wanted to stress that Turkey is fighting terrorism from Isis as well as Kurds. However, he maintained that there was no appreciation for that from the West, especially the European Union. He complained about lack of action by Brussels on an agreement to allow visa-free travel for Turkish citizens in Europe, and non-payment of money Ankara was supposed to get in return for stemming the flow of refugees into Europe. He also decried “obstacles” on Turkey’s long-running application to join the European Union.

“On the question of membership, we need the European Union to define its vision: to tell us how they see the future,” said Mr Yildirim. “Is it going to be a Christian club? Is it the case that we will not be accepted because we are a Muslim country? If that is the case, then we will respect that. But we need to be told.

“We have completed all the requirements demanded by the European Union for visa-free travel, except one: changes to our counter-terrorist laws. We cannot do what they are asking while we are facing such a terrorist threat: not a threat just to us, but Europe. So we have not got visa-free travel. They have given this visa-free arrangement to the Ukraine, Georgia, countries in Latin America, the GCC (Gulf Cooperation Council) but not Turkey.

“The EU was supposed to give $3 billion as part of the refugee agreement. But they have sent around $800 million. But this is not about money for us; we will continue with our end of the agreement.”