Israeli Prime Minister Benjamin Netanyahu expressed his "appreciation" to the United States for opposing an Arab plan for a nuclear weapons-free zone in the Middle East, an Israeli official said.

The Jewish state is believed to be the only country in the region that has an atomic bomb although it has never confirmed its nuclear military capacity.

The Saturday phone call between Netanyahu and US Secretary of State John Kerry came with the two governments locked in bitter disagreement over American-led efforts to reach a nuclear deal with Iran, which Israel says could compromise its security.

A month-long UN conference reviewing the nuclear Non-Proliferation Treaty (NPT) ended Friday without agreement, after the US, Canada and Britain opposed a proposal backed by Egypt and Arab countries to convene a conference by March 2016 on creating a Middle East nuclear-weapons free zone.

Netanyahu spoke with Kerry "to convey his appreciation to President Obama and to the secretary (of state) for the position taken," the official said.

"The United States kept its commitment to Israel by preventing a Middle East resolution that would single out Israel and ignore its security interests and the threats posed to it by an increasingly turbulent Middle East."

Israel also appreciated the British and Canadian decision "to reject the coordinated diplomatic effort against Israel at the conference," the official said in a statement.

Israel is not a member of the NPT but attended the conference as an observer.

President Barack Obama told American Jews on Friday that his "commitment to Israel's security is and always will be unshakeable".

"There will be disagreements on tactics when it comes to how to prevent Iran from getting a nuclear weapon, and that is entirely appropriate and should be fully aired," Obama said.