Turkey's President Recep Tayyip Erdogan held talks with a senior Hamas delegation on Saturday.
The gathering was understood to have been timed to coincide with US Secretary of State Mike Pompeo's visit to Israel and the Middle East, which begins today.
Hamas’s military wing has been designated by the UK and the EU as a proscribed terrorist organisation since 2001.
The Gaza militant group said it briefed Mr Erdogan on the “Palestinian cause” and complained about Israel’s annexation plans.
Hamas head Ismael Haniyeh said he “congratulated Erdogan on the advent of a new Hijri year, discovery of a new natural gas field and the reopening of the Aya Sofia Mosque.” The Aya Sofia is one of two ancient churches the Ankara regime recently turned into mosques, prompting uproar in the West.
The meeting was the latest in a series of meetings between Hamas and members of Mr Erdogan’s government.
Both Hamas and Turkey’s ruling party have roots in the Islamist movement the Muslim Brotherhood, which is banned in several Arab states.
The Ankara meeting comes in the wake of the Israel-UAE agreement to establish diplomatic and economic ties.
Hamas, Iran and Turkey all oppose the deal and see it as a threat to their ability to influence the region.
Turkey reportedly wants to unite Hamas, Qatar and the Government of National Accord in Tripoli in as part of a grand coalition against the UAE, Israel, Egypt, Greece and others.