ISTANBUL -- Turkey's president accused the European Union on Friday of failing to deliver funds it promised as part of a deal to stop migrants crossing the Aegean Sea, adding to fears that the agreement which has curtailed last year's huge refugee surge to Europe's heartland is about to collapse.

Recep Tayyip Erdogan said the EU had pledged 6 billion euros ($6.7 billion) in support of some 3 million refugees Turkey currently hosts, but has delivered only 183 million euros.

"What happened?" Erdogan asked before heading for the G20 summit in China. "No country can stand alone in this crisis. Unfortunately the promises on this issue are not kept."

EU spokeswoman Maja Kocijancic denied the charges, saying billions it is providing "is funding for refugees and host communities, not for Turkey."

When the agreement was announced in March, the EU said only that the money would be disbursed "in close co-operation" with the Turkish government.

The row between Turkey and the EU comes a year after the lifeless body of 3-year-old Aylan Kurdi was photographed on a Turkish beach, drawing the world's attention to the plight of hundreds of thousands refugees who have used the treacherous route across the Aegean while escaping wars and poverty in their countries.

Along with up to 6 billion euros promised through 2018 to help the mostly Syrian refugees Turkey is hosting, the incentives for Turkey to agree the migrant deal included fast-track EU membership talks -- as well as the visa waiver, which is conditional on Turkey modifying its definition of terrorism and what constitutes a terror act to ensure that journalists and academics aren't arrested.

Erdogen's comments came a day after visiting European Parliament President Martin Schulz failed to persuade his hosts to amend the tough anti-terrorism laws in exchange for lifting visa restrictions for Turkish nationals -- a key incentive in the deal.

The request was emphatically rejected.

"We have once again bluntly told the EU and Mr. Schulz that we cannot make an improvement in the Struggle Against Terrorism Law during the current conditions in the country," Prime Minister Binali Yilderim said.

"Regarding the prevention of illegal migration, we stand behind our promises. We expect EU countries to do the same. Even the night of the (July 15) coup attempt, the Turkish coast guard saved 2,000 migrant lives. That's how much we care about life," he said on Friday.

Turkish officials maintain they cannot make the amendments to the anti-terror laws at a time when they are fighting heightened threats from Kurdish rebels and the Islamic State group.

Turkey has also launched a crackdown after the failed military coup, rounding up tens of thousands of alleged supporters of U.S.-based Islamic cleric Fethullah Gulen. The government blames Gulen for the uprising that left at least 270 people dead, and considers him and his followers to be terrorists. Gulen denies any involvement.

Over 1 million migrants and refugees entered Europe via Turkey and Greece last year. The flow slowed to a trickle earlier this year after Austria set in motion a string of border closures that shut down the Balkan refugee route to the European heartland and Turkey's then-prime minister, Ahmet Davutoglu, hammered out the deal with Brussels.

The apparent impasse between Ankara and Brussels now threatens the whole project.

Amanda Paul, senior policy analyst and Turkey specialist at the European Policy Center, an independent Brussels think-tank, said that the deal was "hanging by a thread" and had been flawed from the beginning -- though she said it's impossible to predict whether and how long it will last.

"It's clear that the agreement is probably more important in the scale of things to the EU than it is to Turkey," she said. "I doubt whether the EU has a B plan -- they basically had no A plan, let alone a B plan ... it would cause a significant crisis, and where they would go from there is an open question."

------

Associated Press writers John-Thor Dahlburg in Brussels and Geir Moulson in Berlin contributed.