Although Ukraine has never produced its own nuclear weapon to this day, we should bear in mind that back in the days, Ukraine possessed approximately 5,000 nuclear weapons. This is all due to the fact that before 1991, Ukraine was a part of the Soviet Union. However, as a consequence of its dissolution, all the countries that were satellites or were forcefully attached to Soviet Union, received number of warheads. They were once the property of the Soviet Union. Nevertheless, after Ukraine became independent, they received everything that was the part of the USSR, even nuclear warheads. As a result of that, Ukraine became the third largest holder of nuclear weapons in the world.
Ukraine decided to get rid of these weapons quite quickly. Three years later, in 1994 that is, they joined Nuclear Non-Proliferation Treaty. In 1996, all the warheads were moved and disassembled in Russia.