Here's how many nukes each nuclear country in the world has

Thomson Reuters

Russian Yars RS-24 intercontinental ballistic missile system drives during Victory Day parade to mark end of World War Two at Red Square in Moscow.

• Curbing North Korea's nuclear weapons program has been a priority for President Donald Trump.
• North Korea, however, has very few nuclear weapons stockpiled compared to other countries around the world.
• Only eight other countries currently control the world's 15,000 nuclear weapons.

Since President Donald Trump assumed office, there has been an intense focus on North Korea's nuclear weapons program, which North Korean leader Kim Jong Un has refused to halt. Trump has criticized and mocked Kim in response, and put pressure on countries like China to persuade the rogue state to stop building up its arsenal.

Eight other countries, including the United States, have stockpiled nuclear weapons for decades.

A few years after the US dropped atomic bombs on Japan during World War II - the first and only time nuclear weapons have been used in combat - Russia began developing its own nuclear capabilities. The United Kingdom, France, and China followed soon thereafter.

By the 1960s, it was becoming apparent that a future in which dozens of countries build and test nuclear weapons would not be safe for the world. This led to the nuclear Nonproliferation Treaty of 1968, which was designed to prevent the spread of nuclear weapons and nuclear technology. A handful of countries, including Israel and North Korea, have not signed on to the agreement.

The treaty has been largely successful. But the potential use of nuclear weapons between hostile nations continues to threaten international peace.

Here's how many nuclear weapons exist, and which countries have them, according to a report from the Federation of American Scientists: