Israel has accused Turkey of contributing to the finances of Islamic State through purchases of ISIS-trafficked oil, BBC News wrote. Israel’s Defence Minister, Moshe Yaalon, said that IS had “enjoyed Turkish money for oil for a very, very long period of time”, adding that Turkey had “permitted jihadists to move from Europe to Syria and Iraq and back”. He also said that it was up to the Turkish leadership to decide if it wanted to be part of “any kind of cooperation to fight terrorism.”

His Greek counterpart, Defense Minister, Panos Kammenos, made a similar statement noting that a large part of ISIS’s oil trade, as well as the financing of terror, is going through Turkey, according to Russia Today. Initially, Russia had raised these allegations against Ankara in December 2015, releasing maps and satellite images to prove that Turkey was the main consumer of oil smuggled out of Syria and Iraq by IS. The United States rejected these claims last month.

It is feared that these charges will block any progress towards normalization of Israeli-Turkish relations and with that the negotiations to import Israeli natural gas ongoing since December may be halted. Turkey wants to import gas from Israel as an alternative to Russia, where it currently gets 50% of its gas supplies, following the dispute with Moscow over Turkish downing of a Russian fighter jet operating in Syria, as the Financial Times reported in December.

Diplomatic relations between Turkey and Israel had been discontinued in 2010 after the Israeli navy raided a flotilla of ships trying to break Israel’s blockade of Gaza. Ten Turkish activists were killed on one of the aid ships and the Turkish government has insisted on compensation for their deaths, another key point of dispute in attempts to normalize relations.