US congressmen urged President Barack Obama to refrain from the concept of a preemptive nuclear strike.

MOSCOW (Sputnik) – Over 20 US congressmen signed a letter, demanding President Barack Obama to discard the concept of the possibility of a preemptive nuclear strike.

"In case the United States implements its possible plans to be the first to use nuclear weapons against an enemy with the similar arsenal, [this] may result in full-scale nuclear exchange and deaths of thousands of its citizens," the letter said.

The United States and Russia are the only states maintaining the so-called nuclear triad, consisting of land, naval and air nuclear weaponry.

Both top nuclear powers are currently engaged in extensive nuclear modernization, according to both countries’ defense agencies.

By the early 2040s, the United States is expected to replace and upgrade all three legs of its nuclear triad, amounting to costs that some experts have put at close to $1 trillion.

Nuclear weapons remain a key component of the US national defense strategy and officials have maintained their commitment to protecting the nuclear deterrent.

Earlier, the New York Times editorial reported that the White House considered adopting declaration on the policy of no-first-use of nuclear weapons, however US President Obama rejected the declaration.