Here's a look at what you need to know about nuclear nations.
Information about nuclear stockpiles varies from source to source. The information below is sourced to the Nuclear Threat Initiative.
Countries with confirmed nuclear weapons: China - 260 warheads, 50-60 nuclear capable intercontinental ballistic missiles (ICBMs).
France - Approximately 290 warheads.
India - 90-110 nuclear warheads.
Pakistan - 90-110 nuclear warheads.
Russia - 1,765 warheads on 523 strategic nuclear delivery systems.
United Kingdom - Approximately 225 strategic warheads.
United States - 1,411 deployed warheads on 673 delivery systems.
Countries with unconfirmed nuclear weapons: Israel - Suspected to have enough plutonium for 100-200 nuclear weapons.
North Korea - It is estimated that North Korea could have 30 to 60 nuclear weapons, according to Washington Post reporting.
Countries suspected of developing nuclear weapons:
Iran - World powers, including the United States, want to curb Iran's nuclear program to keep it from developing a nuclear bomb. For more details on Iran's program, visit Iran's Nuclear Capabilities Fast Facts.
July 14, 2015 - After 20 months of talks, negotiators finalize a landmark nuclear deal between Iran, the United States and five other countries. The Joint Comprehensive Plan of Action (JCPOA) states "Iran reaffirms that under no circumstances will (it) ever seek, develop or acquire nuclear weapons." The agreement, which has a 15-year time frame, requires Iran to reduce its centrifuges by two-thirds. It also bans enrichment at key facilities. In exchange, the country will get relief from economic sanctions and permission to continue its atomic program for peaceful purposes.
Countries that have the ability to build nuclear weapons, but claim not to have any nuclear ambitions: Japan - On November 30, 2006, Japanese Foreign Minister Taro Aso stated that Japan possesses the knowledge and ability to produce nuclear weapons, but has no plans to do so.
Countries that have abandoned nuclear weapons or weapons programs in recent years: Belarus - Still has a civilian nuclear program.
Kazakhstan - Although it inherited nuclear warheads after the collapse of the Soviet Union, Kazakhstan dismantled them.
Ukraine - After the collapse of the Soviet Union, Ukraine had the third largest arsenal of nuclear weapons. The weapons were transferred back to Russia.
South Africa - Became a "non-nuclear weapons state" in 1991.