President Donald Trump revealed Thursday that he wanted to expand the nation's nuclear weapons arsenal as the U.S. did not possess the largest stockpile in the world.

Speaking to Reuters, Trump pledged the U.S. was "never going to fall behind any country even if it’s a friendly country" and said he hoped the U.S. would become "top of the pack" in reference to the nine nations believed to possess such weapons of mass destruction. White House Press Secretary Sean Spicer later expanded, saying the administration planned to "maintain America’s dominance around the world."

Trump had previously expressed his desire to expand the U.S. nuclear arsenal in December when he and Russian President Vladimir Putin made separate, coinciding statements in support of bolstering their respective nations' nuclear capabilities. In Trump and Putin's first ever phone call earlier this month, Trump reportedly stated that he would like to renegotiate the New Strategic Arms Reduction Treaty (START) adopted under predecessor Barack Obama. The treaty, signed in 2010, sought to cut in half the U.S. and Russia's nuclear arsenals and succeeded the START 1 signed by the Washington and Moscow in the final days of the Soviet Union in 1991.

Trump and Putin have considered one another political allies, however, Russia has been the only nation standing between the U.S. and the "top of the pack." Russia was estimated to possess about 7,300 nuclear warheads, while the U.S. maintained around 6,970, according to 2015 figures by the Federation of American Scientists. While Russia and the U.S. remain far ahead in the international ranking of nuclear arms, both allies and foes of Washington maintain their own stockpiles of the formidable weapons.

After the U.S. and Russia, the next most nuclear-capable nation was France, with about 300 nuclear warheads. China, which is estimated to have about 260 weapons in its nuclear stockpile, has antagonized the U.S. and its Asia-Pacific allies by exercising vast claims in the South China Sea and Yellow Sea. Another U.S. ally, the U.K., followed with about 215 nuclear weapons. These five countries were all recognized by the U.N.'s 1968 Non-Proliferation of Nuclear Weapons Treaty. However, the nuclear-armed list did not end there.
The conflict between Pakistan, with an estimated 130 nuclear weapons, and India, with an estimated 120 nuclear weapons, has been a geopolitical flashpoint for decades and a potential escalation would likely be devastating for populations well beyond the two nations' borders. Israel has neither confirmed nor denied possession of an estimated 80 nuclear weapons and refused international inspections of sites suspected of being nuclear facilities.

Lastly, North Korea has routinely boasted about its nuclear weapon advancements in recent years and experts have estimated the reclusive, authoritarian state to possess about 10 nuclear warheads. However, doubt has been cast on Pyongyang's launching capability.