JERUSALEM, May 21 (Reuters) - The U.S. administration of President Barack Obama will not force Israel to state publicly whether it has nuclear weapons, an Israeli official said on Thursday.

He said Washington would stick to a decades-old U.S. policy of "don't ask, don't tell".

Obama's bid to curb Iran's nuclear programme through diplomacy has stirred speculation that, as part of a regional disarmament regimen, Israel could be asked to come clean on its own secret capabilities.

But a senior Israeli diplomat, speaking after Prime Minister Benjamin Netanyahu held his first summit with Obama in Washington this week, said: "This has never happened, nor will it happen with this administration."

That U.S. message had been conveyed, the diplomat said, "on the various levels of our bilateral talks".

Israel is widely believed to have procured the Middle East's only nuclear weapons. It neither confirms nor denies this, under an "ambiguity" policy billed as deterring foes while avoiding the kind of public provocations that can trigger arms races.

Historians say that the Nixon administration forged a tacit policy of not pressing Israel on the matter. The official American reticence angers Iran -- which denies seeking the bomb -- as well as the Arab world. (Writing by Dan Williams; Editing by Myra MacDonald)