Ismail Haniyeh
Ismail HaniyehWissam Nassar/Flash 90

Ismail Haniya, the leader of the Gaza-based Hamas terrorist organization, said Thursday Hamas rejected next week's US-sponsored Middle East economic conference in Bahrain as it would amount to Arab "normalization" of ties with Israel.

In a rare briefing with international journalists, Haniya also accused Israel of failing to abide by agreements meant to ensure calm in the Hamas-controlled Gaza Strip.

"We clearly express our rejection and non-acceptance of any Arab or Islamic country holding such a conference, which constitutes normalization with the occupation," Haniya said, referring to Israel.

US President Donald Trump's administration organised the conference, which is to be held on June 25 and 26 in Manama for the unveiling of the economic component of a US Israeli-Arab peace plan.

Trump's son-in-law Jared Kushner has been drafting the long-awaited plan, but it has been rejected in advance by the Palestinian Authority, which accused the Trump administration of pro-Israel bias.

The political part of the conference is likely to be delayed until at least after the Israeli elections in September, and probably until November, after a new government has been formed.

The Palestinian Authority has also accused the United States of trying to use the potential offer of billions of dollars in investment to avoid dealing with political causes of their suffering, including what they called Israel's "occupation".

"We reject the Manama conference and the transformation of the Palestinian cause from a political cause to an economic cause," Haniya said.

Haniya also appealed to Bahrain's King Hamad "not to hold this workshop," vowing protests "in all the Palestinian lands and beyond".

Hamas and Israel have fought three wars since 2008 and fears of a fourth remain.

An agreement reached in November is supposed to ensure calm in exchange for Israel easing its blockade of the Gaza Strip.

The Jewish state has never publicly confirmed the deal but has allowed Qatar to bring millions in cash and investments into the Hamas-ruled enclave since then.

In May the two sides came close to a new conflict, with the Hamas and Islamic Jihad terror groups firing hundreds of rockets from Gaza and the Israeli military striking dozens of terrorist targets in response.

Haniya accused Israel of not implementing the agreements reached.

"The understandings today are in the danger zone, due to the failure of the (Israeli) occupation to implement what was agreed upon."

He highlighted the distance Israel allows fishermen from Gaza to operate off the coast, saying Israel had pledged to allow it up to 18 nautical miles off the coast.

Last week Israel banned all fishing off the coast, though it has since resumed to six miles.

"The Israeli occupation uses this range as a form of blackmail," said Haniya.

"We are not against a just peace (with Israel) based on just rights but we are against surrender," he added.

Israel says the restrictions are necessary to isolate Hamas, saying the terror group often seeks to smuggle weapons into the Gaza Strip.