Nuclear weapons

Iran has no missile or nuclear cooperation with North Korea, President Mahmoud Ahmadinejad said on Monday, after North Korea conducted a second and far more powerful nuclear test.

The consequences of Iran acquiring a nuclear weapon would be calamitous and major powers must act together to prevent it, the top U.S. military officer said on Thursday.

News reports about Pakistan's nuclear arsenal, including questions about its safety, are part of a malicious campaign that is counter-productive to efforts to defeat terrorism, a Pakistani spokesman said on Thursday.

The United States must allay Russian concerns over its planned anti-missile system in Europe if the two sides are to achieve a breakthrough on cutting nuclear weapons, Russia's foreign minister said on Wednesday.

Vast stockpiles of nuclear weapons amassed during the Cold War could become the catalyst for a thaw in relations this week between the United States and Russia.

North Korea on Wednesday threatened a new nuclear test unless the U.N. Security Council apologizes for tightening sanctions, confirming some analysts' fears that Pyongyang was determined to build an atomic arsenal.

U.S. President Barack Obama discussed North Korea's missile and nuclear weapons threat with Japan’s Prime Minister Tarso Aso in a telephone talk Friday.

Negotiators from the United States and Russia will take the first steps toward a new treaty to curb nuclear arms Friday, part of an effort to improve relations.

Russia responded cautiously on Monday to U.S. President Barack Obama's plans for a nuclear-free world, saying a number of conditions would need to be met for the vision to become reality.

North Korea has ordered U.N. inspectors to leave its Yongbyon complex, after saying it would quit international nuclear disarmament talks and restart the plant that makes bomb-grade plutonium.

Turkish President Abdullah Gul called on Wednesday for a Middle East free of weapons of mass destruction, hoping that a U.S.-Russian pledge to join forces to eradicate nuclear weapons will encourage the region.

Iran criticized on Monday U.S. President Barack Obama for saying Tehran posed a threat with its nuclear program and urged Washington and other countries possessing atom weapons to dismantle their arsenals.

U.S. President Barack Obama called on Friday for a world without atomic weapons and urged allies to stand firm against Iran's nuclear ambitions and a planned missile launch by North Korea.

Russia and the United States will pursue a new deal to cut nuclear warheads, presidents Dmitry Medvedev and Barack Obama said on Wednesday, making good on a pledge to rebuild relations from a post-Cold War low.

Senator Hillary Clinton said Monday that America's gravest threat is that terrorists will obtain weapons of mass destruction.

Iran halted its nuclear weapons development program in the fall of 2003 under international pressure but is continuing to enrich uranium, which means it may still be able to develop a weapon between 2010 and 2015, senior intelligence officials said Monday.

Assistant Secretary of State Christopher Hill said on Tuesday he believed North Korea would stop its uranium enrichment program by the end of the year.

The United States and India said on Friday they made substantial progress in negotiations on a landmark nuclear cooperation agreement, and one U.S. official told Reuters the long-delayed deal was effectively done.

India has strongly urged Australia to change its nuclear policy and supply uranium to power its booming economy.

The U.S. Department of Homeland Security said on Friday it awarded $1.16 billion in contracts to three companies to develop equipment to scan cargo at border cities for nuclear weapons material.