Preview: Nuclear Security Summit In Washington‬

This week’s nuclear security summit in Washington, D.C. is the largest gathering of world leaders hosted by a U.S. president since the 1945 conference founding the United Nations.

But the historic two-day gathering of 47 world leaders is not expected to result in a bold new strategy.

Rather, according to top Obama Administration officials, the summit will showcase President Obama’s eagerness to lead on the issue.‬

Obama invited world leaders to Washington as a key step toward his declared goal of one day having a world without nuclear weapons.

The president hopes to use the gathering to focus the world on what he sees as one of the most serious nuclear proliferation threats right now: the ability of terrorists, like al-Qaida, to steal or buy nuclear material.‬

"We don't believe the threat from nuclear terrorism comes from states,” said Secretary of State Hillary Rodham Clinton on ABC’s “This Week.”‬ “Our biggest concern is that terrorists will get nuclear material."

Iran and North Korea were not invited to the summit, although both of the nations’ nuclear programs are likely to be discussed during the Washington summit on Monday and Tuesday.‬ “We fear North Korea and Iran because their behavior as -- in the first case, North Korea being -- already having nuclear weapons, and Iran seeking them -- is that they are unpredictable,” said Clinton on “This Week”.

Also likely to come up is the last minute decision by Israel’s Prime Minister Benjamin Netanyahu to cancel his plans to attend the summit. Clinton downplayed Netanyahu’s decision to send a deputy to Washington instead.

“The Israeli government will be represented at a very high level,” added Clinton. “And you know, they are - they share our deep concern about nuclear terrorism."‬

The nuclear security summit officially starts on Monday. But Obama held a series of pre-summit one-on-one meetings Sunday afternoon with the leaders of India and Pakistan, nuclear-armed neighbors.

Obama also met with leaders from South Africa and Kazakhstan, countries which have gone nuclear free, giving up their nuclear weapons programs.‬

Obama starts the summit off on Monday with a dinner. He will also meet individually with the leaders of Jordan, Malaysia, Armenia and China. Obama Administration official say they hope to conclude the summit on Tuesday with a “unifying statement that commits the attendees to keep working” on nuclear security.‬