"These are serious questions, and it's a real shame that there's a tendency to underestimate them", Putin continued, according to Reuters.
Putin had a lot more to say, however, on issues relating to the Intermediate-Range Nuclear Forces Treaty and nuclear weapons in general, U.S. President Donald Trump's announcement that American troops will withdraw from Syria, and the recent clash between Russian Coast Guard and Ukrainian naval vessels in the Black Sea.
The world is facing a rising threat of a nuclear war because of the US pullout from arms control treaties and its destabilizing military plans, Russian President Vladimir Putin said today.
Any such inspections - if they were to happen - should not be unilateral but should take place in both countries, he added.
"It's very hard to imagine how the situation will develop (if the US quits the INF treaty)".
Speaking of the U.S., he went on: "Now they're is making another step and they are withdrawing from the INF treaty so what's going to come out of that".
He said: "There is always an error margin and we should let the escalation happen. The move put the full weight of the alliance behind the USA, which has given Russian Federation until February to come into compliance or trigger Washington's withdrawal from the treaty". Putin said he was anxious that Washington didn't appear to be interested in discussing its future. "Lowering the threshold could lead to a global nuclear catastrophe", he said.
Putin admitted he was still unclear what the US withdrawal will mean in actual practice, a common refrain heard from even American allies in the past hours seemingly caught off guard by the Trump declaration. Putin said. "We are witnessing the collapse of the global system of deterrence".
Russia-U.S. ties have sunk to their lowest levels since the Cold war times over the Ukrainian crisis, the war in Syria and the allegations of Russian meddling in the 2016 U.S. presidential election, among other disputes.
During the almost four-hour news conference, Putin maintained Russian Federation was not interested in "gaining unilateral advantages".
The deal bans ground-launched medium-range missiles, with a range of 500-5,500km (310-3,400 miles). The pullout is also likely to strengthen Russia's role in Syria's future.
Putin showed no sign of backing down from Russia's stance on Ukraine.
Putin showed no sign of backing down from Russia's stance on Ukraine, and accused his Ukrainian counterpart of provoking a naval stand-off with Russian Federation to boost his electoral prospects.
Economic questions dominated the opening exchanges, with Vladimir Putin beginning as usual by reeling off growth figures.
The positive statistics follow a hard period in recent years when Russia's economy has suffered a combined blow of low oil prices and Western sanctions, resulting in stagnation. He drew skepticism even from state TV as he touted the year's growth outlook of 1.8 percent and an upturn in household incomes.
Putin pledged that the government will create incentives to speed up growth.