An intercontinental ballistic missile (ICBM) is a ballistic missile with a range greater than 5,500 kilometres (3,400 mi), primarily designed for nuclear weapons delivery. Conventional, chemical, and biological weapons can also be delivered with varying effectiveness, but have never been deployed on ICBMs. Most modern designs support multiple independently targetable reentry vehicle (MIRVs), allowing a single missile to carry several warheads, each of which can strike a different target. The United States, Russia, China, France, India, the United Kingdom, Israel, and North Korea are the only countries known to have operational ICBMs. Pakistan is the only nuclear-armed state that does not possess ICBMs.