Dutch prime minister Mark Rutte has had informal talks with Turkey’s president Recep Tayyip Erdogan on the fringes of the current UN humanitarian summit in Istanbul.

‘I expressed our concerns about the decision to scrap immunity for Turkish MPs and we reflected on how to put the agreement on migration made between the EU and Turkey into practice,’ the prime minister said on Facebook.

In addition, the two leaders talked about strengthening the Nato mission in the Aegean sea, he said. ‘Although it is too soon to draw definitive conclusions, the agreement would appear to be paying off,’ he said. ‘We want to wreck the boat smugglers’ business model.’

It was important to meet other aspects of the agreement, such as the visa shake-up for Turkish nationals, but this could only happen when Turkey had fully met its obligations, Rutte said.

Rutte also said he had raised the issue of Dutch newspaper columnist Ebru Umar, who may face charges of insulting Erdogan after sending out several tweets during a holiday.

Umar was banned from leaving the country but was allowed to leave after 17 days.