Russian President Vladimir Putin warned that a war between the United States and Iran would be a “catastrophe,” remarks that came as tensions between Washington and Tehran continue to escalate.

He made the comment during an annual televised "direct line" with the Russian public Thursday, an event that usually runs for hours and is heavily censored.

When asked about the possibility of a U.S.-Iran war, Putin said it’s a scenario he hopes not to see.

“It would be a catastrophe, for the region at the very minimum, because it will lead to an increase of violence, and potential increase in refugees from the region,” the Russian president said. “But also, for those who would attempt it, it could have possibly sad consequences.”

The U.S. accused Iran of attacks on two oil tankers in the Gulf of Oman last week, which Iran has denied. And Thursday, U.S. military officials said a U.S. drone was shot down in international airspace above the Strait of Hormuz, contradicting Iran's claim that it had struck the aircraft after it entered Iranian airspace.

Both countries insist they don’t want war, but there are concerns about the possibility of a full-blown military conflict should tensions escalate further.

Putin said that Iran is ready to go “to the extremes” to defend itself, and that it’s hard to tell where that would lead.

He also said that he is satisfied that Iran has been abiding by its nuclear agreements, and that “the application of sanctions against it are not justified.”

President Donald Trump’s administration pulled out of an international nuclear agreement with Iran last year and reimposed sanctions on the country.

Putin also weighed in on the possibility of improving ties between Russia and the U.S.

Diplomatic relations between the two countries turned sour in light of Russia’s alleged role in the military conflict in eastern Ukraine, its annexation of Crimea, meddling in the 2016 U.S. presidential election, and the poisoning of a former Russian spy in the United Kingdom last year, for which most western allies have blamed Moscow.

Putin said Russia was ready for dialogue with the U.S. if the Americans agree to reciprocate.

But he suggested that the realities of U.S. politics could tie Trump’s hands when it comes to Russia.

“Even if the president wants to make steps towards each other, wants to talk about something, there are multiple restrictions coming from other institutions of power,” Putin said.

He added: “I don’t think things will be easy in our relations considering that part of the U.S. establishment is trying to speculate on the Russian-U.S. relations and gain something for itself."

Putin also slammed American measures against Chinese tech giant Huawei, saying they are a means to "hold Chinese development back."

His comments come as relations between Moscow and Beijing have been blossoming, to the alarm of some U.S. policymakers.

When the Russian leader was asked about sanctions that have been imposed on Russia since 2014 when it annexed Ukraine’s Crimean peninsula and was accused of backing pro-Russian separatists in Ukraine’s eastern region of Donbass, Putin said that even if Russia “totally surrender[ed] and spit on our fundamental interests" to reverse the sanctions, nothing would fundamentally change.

He compared the situation to tariffs imposed on China by the U.S., saying they are “essentially sanctions.”

Negotiations between Beijing and Washington took a turn for the worse in early May with a tariff hike on $200 billion worth of Chinese goods exported to the U.S., and an effective ban on American companies doing business with Huawei.

The U.S. has begun investigating whether $300 billion of other Chinese goods could be subject to tariffs.

Beijing responded with tariffs on $60 billion worth of U.S. goods.

“Look at China,” Putin said Thursday. “It has nothing to do with Crimea or Donbass. You know how we are being blamed for occupying Donbass, which is absurd and a lie. China has nothing to do with that, but the tariffs on their goods — consider them sanctions — are growing and growing.”

He also addressed U.S. restrictions against Huawei.

“Where did that come from and what is the reasoning behind it,” Putin said. “The reasoning is holding Chinese development back. [China] has become a global competitor of another global power — the United States. The same is happening towards Russia and will be happening in the future.”

During the almost 4.5-hour conference, Putin also tackled a number of questions concerning Russia's internal affairs, including falling real incomes, corruption, Internet freedom, health care and utility tariffs.

The moderators alleged a hacking attack “from abroad” was launched on the call center that was taking in questions for the president during the event. There was no immediate information about where exactly the alleged attack came from.