The Russian leader made the comments to Rossiya 1 and RIA Novosti ahead of presidential elections on March 15, in which he is widely expected to sail through to a fifth term in office, and as his full-scale war in Ukraine grinds into a third year.

Putin said that from a military and technical standpoint, Russia is ready for a nuclear war, though he didn’t say one was imminent.

He warned that if US troops were deployed to Ukraine, Russia would treat them as interventionists.

“Apart from (US President Joe) Biden, there are enough other experts in the sphere of Russian-American relations and strategic restraint. So I don’t think that everything is going to go head-on here, but we are ready for it,” Putin said.

Putin said the United States is also developing nuclear forces but that doesn’t mean they are ready to “launch a nuclear war tomorrow.”

“They are now setting tasks to increase this modernity, innovation, they have a corresponding plan. We know about it too. They are developing all their components. So are we,” Putin said.

“Weapons exist in order to use them. We have our own principles.”

Russia sees its large and diverse nuclear weapons stockpile as an important tool for achieving its goals in a potential conflict with the United States or NATO, the US intelligence community believes, and its struggles on the battlefield in Ukraine have continued to raise the risk that he might use them.

“Russia’s inability to achieve quick and decisive battlefield wins, coupled with Ukrainian strikes within Russia, continues to drive concerns that Putin might use nuclear weapons,” the intelligence community wrote in its annual unclassified threat assessment, released on Monday.

In late 2022, the US began “preparing rigorously” for Russia potentially striking Ukraine with a tactical battlefield nuclear weapon, according to reporting in a new book by CNN’s Jim Sciutto, “The Return of Great Powers.”

Russia is also expanding and modernizing the systems it has for delivering nuclear weapons, the intelligence community report stated, “because Moscow believes such systems offer options to deter adversaries, control the escalation of potential hostilities, and counter US and Allied conventional forces.”

These include long-range nuclear-capable missiles and underwater delivery systems meant to penetrate or bypass US missile defenses, according to the report.

Earlier this month, two senior US administration officials told CNN that in late 2022, the US began “preparing rigorously” for Russia potentially striking Ukraine with a nuclear weapon.

The Biden administration was specifically concerned Russia might use a tactical or battlefield nuclear weapon, the officials said.

Last year, Putin deployed tactical nuclear weapons to neighboring ally Belarus, and former Russian President and deputy chairman of Russia’s Security Council Dmitry Medvedev said strategic nuclear weapons could be used to defend territories incorporated into Russia from Ukraine.

Speaking to Russian state media, Putin said Western countries thought they could “do away” with Russia at the start of the Ukraine invasion, but instead, he claimed Moscow’s financial and economic systems are stable, and the capabilities of its armed forces are only growing.

NATO intelligence estimates of Russian defense production suggest that Russia appears on track to produce nearly three times more artillery munitions than the US and Europe, a key advantage ahead of what is expected to be another Russian offensive in Ukraine later this year. It’s also running artillery factories “24/7” on rotating 12-hour shifts, a NATO official said.

However, Russia’s ramp-up is still not enough to meet its needs, US and Western officials say, and Western intelligence officials do not expect Russia to make major gains on the battlefield in the short term.

Meanwhile, Ukraine is in desperate need of US aid for arms and armaments, with Ukrainian President Volodymyr Zelensky saying “millions” could die without it.

The Biden administration announced another package of military aid to Ukraine worth up to $300 million on Tuesday but Biden said it was “not nearly enough,” and Congress needs to pass additional funding.

In his interview with state media, Putin said Russia would be willing to negotiate on Ukraine, but only if based on reality.

“Are we ready for negotiations? Yes, we are ready, but only ready for negotiations, not based on some desires after the use of psychotropic drugs, but based on the realities that have developed, as they say in such cases, on the ground,” Putin said.

Asked if there could be a “fair agreement” with the West, he said, “I don’t believe anyone, but we need guarantees.”

Zelensky has previously rejected suggestions it was time to negotiate peace with the Kremlin and has repeatedly said he would not give up Ukrainian territory.

“When you want to have a compromise or a dialogue with somebody, you cannot do it with a liar,” he told CNN in September.

Also during the interview with Rossiya 1 aired Wednesday, Putin said Ukrainian attacks on Belgorod and Kursk are happening amid Kyiv’s “failures” on the battlefield. The goal of Ukraine’s attacks, he added, is to interfere with Russia’s upcoming election.

CNN’s Katie Bo Lillis contributed to this report.