ANKARA — Negotiators are close to striking a long-awaited deal on compensation for Turkish victims of a deadly Israeli raid on a Gaza aid flotilla four years ago, a Turkish official said Monday.

The May 2010 Israeli assault on the Turkish ship the Mavi Marmara while it was in international waters on its way to Gaza sent relations between Israel and Turkey to an all-time low.

Talks on compensation for the nine Turks killed in the raid eventually began in March 2013 after Israel extended a formal apology to Turkey in a breakthrough brokered by US President Barack Obama.

“We are close to an agreement” to settle the compensation issue, a Turkish official told AFP on Monday.

Turkish foreign ministry undersecretary Feridun Sinirlioglu was in Israel earlier this month to discuss the terms of an agreement, which will help normalize relations between Jerusalem and its once closest Muslim ally.

Foreign Minister Ahmet Davutoglu acknowledged on Sunday there had been a “momentum” in talks in order to bridge the gaps.

“It would not be correct to provide a timeframe on such (delicate) issues but I can say that serious progress has been made in recent meetings,” Davutoglu told Turkish television.

“A historic step was taken with the apology… Now a second step will be taken with the compensation,” he said.

“We are going through a period where the relations are the closest to normalization after Mavi Marmara.”

The assault triggered an international outcry and a severe diplomatic crisis between Turkey and Israel, with Ankara expelling the Israeli ambassador, demanding a formal apology and compensation.

Israeli media reports have said the compensation talks were revived in December when Israeli negotiators travelled to Istanbul and Turkey lowered its demands, which was neither confirmed nor denied by the Turkish side.

Passengers on the deck of the Mavi Marmara on May 31, 2010 (Photo credit: IDF Spokesperson's Office/ Flash 90)

Passengers on the deck of the Mavi Marmara on May 31, 2010 (Photo credit: IDF Spokesperson’s Office/ Flash 90)

The amount of compensation to be paid, as well as the legality of a final agreement, are believed to be sticking points but the two sides appear to be narrowing their differences.

Last week, Haaretz reported that Israel has offered $20 million in compensation to the families of those killed and wounded in the flotilla raid.

Western diplomats quoted by the paper said Ankara had demanded $30 million, but Israel was initially willing to give only $15 million.

Prime Minister Benjamin Netanyahu later decided to up Israel’s offer to $20 million, with an extra $3 million available “if necessary to secure an agreement,” the paper said.

Davutoglu refused to disclose the amount of compensation being sought but hinted at “some positive developments.”

He also said he was in constant touch with Prime Minister Recep Tayyip Erdogan to discuss future steps to be taken after a deal including the appointment of an ambassador to Israel.