Both Russia and the United States remain on track to fully implement the New START Treaty, aiming to greatly reduce the number of deployed strategic nuclear warheads by 2018, Under Secretary of State for Arms Control Rose Gottemoeller said.

"Both nations [the US and Russia] are faithfully implementing the [New START] Treaty's inspection regime," Gottemoeller said during a Wednesday speech at the Brookings Institute.

"Even during this severe crisis with the Russian Federation, the Russians are continuing in a businesslike way to implement the New START Treaty," the under secretary of state added.

The State Department official also stated that the Ukrainian crisis sparked tensions in the US-Russian relationship, and progress on arms control negotiations were "complicated by the severity of that terrible crisis." Despite the complications, she noted continuing signs of "pragmatism and a businesslike attitude" toward implementing the New START.

While Russia continues progress on the New START, US lawmakers must make the case in their own political environment that "it is a good thing to pursue strategic arms reduction with the Russian Federation at a time of profound crisis over Ukraine and other significant issues," Gottemoeller noted.

Based on mutual progress, the New START Treaty should be fully implemented by the United States and Russia by February 5, 2018, Gottemoeller said.

Beginning in 2013, the United States has pressured Russia for further nuclear arms reductions amounting to one-third of the levels, outlined in the New START. Russia insists on fulfilling the requirements of START before undertaking additional reductions.

Russian President Vladimir Putin repeated Russia's commitment to nuclear arms reduction during his recent speech to the Valdai International Discussion Club. He reaffirmed that Russia is "ready for the most serious, concrete discussions on nuclear disarmament," and remains committed to continuing talks to reduce nuclear arsenals.