Obama vows to reduce nuclear weapons

President Obama outlined his nuclear-free vision last year in Prague

US President Barack Obama has pledged to cut the number and role of nuclear weapons in America's national security strategy.

Mr Obama, marking the 40th anniversary of the nuclear non-proliferation treaty, said a policy review would go "beyond outdated Cold War thinking".

In a statement, he said he would also continue to seek ratification of the Comprehensive Nuclear Test Ban Treaty.

Mr Obama will host a nuclear security summit in Washington next month.

His officials are also involved in talks with Russia on a replacement for the 1991 Strategic Arms Reduction Treaty (Start), which expired last December.

"The United States reaffirms our resolve to strengthen the non-proliferation regime to meet the challenges of the 21st century as we pursue our ultimate vision of a world without nuclear weapons," he said in the statement.

"In addition, we will seek to ratify the Comprehensive Test Ban Treaty and negotiate a treaty to end the production of fissile material for use in nuclear weapons."

The treaty, which bans all nuclear explosions, was adopted by the UN in 1996 but has not yet entered into force.

"Our forthcoming Nuclear Posture Review will move beyond outdated Cold War thinking and reduce the number and role of nuclear weapons in our national security strategy, even as we maintain a safe, secure and effective nuclear deterrent," Mr Obama added.

President Obama laid out his vision for a nuclear-free world in a keynote speech last year in the Czech capital, Prague.

Officials have said that thousands of nuclear weapons could be cut, in many cases by retiring weapons that are now kept in storage.

All numbers are estimates because exact numbers are top secret.

Strategic nuclear warheads are designed to target cities, missile locations and military headquarters as part of a strategic plan.

Israel

Israeli authorities have never confirmed or denied the country has nuclear weapons.

North Korea

The highly secretive state claims it has nuclear weapons, but there is no information in the public domain that proves this.

Iran

The International Atomic Energy Agency reported in 2003 there had been covert nuclear activity to make fissile material and continues to monitor Tehran's nuclear programme.

Syria

US officials have claimed it is covertly seeking nuclear weapons.