Sergy Shoigu, Russian defence minister said that, "Russia's nuclear stockpile is the largest in the world and it will be almost entirely fitted with new, advanced weaponry in the next few years."

​He also stated that, "The main focus should be made on making stronger strategic nuclear power. The share of advanced military weapons in the Russian nuclear triad 

should constitute at least 90 percent by 2021," at a ministry meeting. Putin said last month that the nuclear modernization effort had already reached 79 percent and that the 90 percent of advanced arms in 2021 would include "missile systems that are capable of confidently overcoming existing and even projected missile defense systems."

Like Putin, Trump also has expressed an eagerness to strengthen his nuclear arsenal and made it clear early on in his tenure as president that he wanted a bigger, stronger U.S. force.

While the Trump administration's debut Nuclear Posture Review has yet to be released, at least one former official who saw a copy of the document said, the Pentagon was now looking to develop smaller, more "usable" nuclear weapons and deter other nuclear powers.

Both Russia and the U.S. have accused each other of violating the 1987 Intermediate-Range Nuclear Forces Treaty, they have also each flirted with the idea of creating these so-called tactical nuclear weapons that have a smaller impact, but some say increase the likelihood of a conflict going nuclear.

Russia and the U.S. have both adopted forms of a "launch under attack" policy, meaning they would not necessarily be opposed to conducting a pre-emptive strike, but only if an existential threat was detected. The International Campaign to Abolish Nuclear Weapons estimated that Russia possessed 7,000 nuclear warheads and the U.S. had 6,800.

Like the leading two powers, nuclear states China, France and the U.K. were all witnesses of the 1970 Nuclear Non-Proliferation Treaty, but India, Pakistan, Israel and North Korea were all believed to also possess nuclear weapons despite not signing the landmark pact.

US and Russia Race to Build New, Stronger Nukes.

U.S. and Russia have reversed decades of non-proliferation (arms limitation) efforts in order to modernize and potentially expand their nuclear weapons warehouse, which both President Donald Trump and his Russian mate , Vladimir Putin, have proclaimed as vital to the national security of their respective countries.