The US State Department said on Friday that the conference could "not be convened because of present conditions in the Middle East and the fact that states in the region have not reached agreement on acceptable conditions for a conference".
It did not spell out when or if the event, originally scheduled for December, would take place.
But Britain, which along with the United States, Russia and the United Nations is ones of the organizers, made it clear that the conference was only being postponed rather than cancelled altogether, saying it backed efforts to hold it next year.
"We support the convening of a conference as soon as possible. We endorse fully the work of the Conference Facilitator, Finnish Under-Secretary of State Jaakko Laajava, to build consensus on next steps," Foreign Office Minister Alistair Burt said in a statement.
"We welcome his commitment to conduct further multilateral consultations with the countries of the region to agree arrangements for a conference in 2013," Burt said.
Washington had feared that the conference, which was to be held in Finland, could be used as a forum to bash Israel, a concern likely to have increased after eight days of Israeli-Palestinian fighting that ended with a ceasefire on Wednesday.
Iran and Arab states often say Israel's presumed nuclear arsenal poses a threat to Middle East peace and security. Israel and Western powers see Iran as the main nuclear proliferation threat, but Tehran denies any nuclear weapons ambitions.
The plan for a meeting to prepare the ground for the possible creation of a weapons of mass destruction-free Middle East was agreed to at a May 2010 conference of 189 parties to the 1970 nuclear Non-Proliferation Treaty, or NPT.
Like nuclear-armed India and Pakistan, Israel has never signed the NPT. It neither confirms nor denies having nuclear arms, although non-proliferation and security analysts believe it has several hundred nuclear weapons.
Even if the talks do occur, Western diplomats and others expect little progress any time soon due to the deep-rooted animosities in the region, notably the Arab-Israeli conflict and Israeli concerns about Iran's nuclear program.
Iran, Israel's arch foe, announced earlier this month it would attend the conference, but some Western diplomats said they thought Tehran may have only done so once it became clear that the meeting was likely to be postponed anyway
LONDON (Reuters) -- Britain said on Saturday it hoped a conference on banning nuclear weapons in the Middle East could take place "as soon as possible", after the United States said it would not be held next month.