Russia has deployed a cruise missile in violation of a Cold War-era arms control treaty, a Trump administration official said Tuesday. A Russian intelligence-collection ship has been operating off the U.S. east coast in international waters, a U.S. defense official told The Associated Press. And NBC News reported that last week four Russian aircraft flew in an "unsafe and unprofessional" manner near a U.S. Navy destroyer in the Black Sea, according to the Pentagon.

President Donald Trump, who has frequently praised Russian leader Vladimir Putin, has not publicly commented on these Russian actions. Instead, he used his Twitter account Wednesday to slam former President Barack Obama's foreign policy toward Russia and leaks to the media.

In a series of tweets Tuesday, Trump attacked media reports that U.S. agencies intercepted phone calls last year between Russians and members of his presidential campaign team.

"The fake news media is going crazy with their conspiracy theories and blind hatred. @MSNBC & @CNN are unwatchable. @foxandfriends is great!" Trump said.

"This Russian connection non-sense is merely an attempt to cover-up the many mistakes made in Hillary Clinton's losing campaign," Trump went on, adding that "Information is being illegally given to the failing @nytimes & @washingtonpost by the intelligence community (NSA and FBI?).Just like Russia."

He later added: "The real scandal here is that classified information is illegally given out by 'intelligence' like candy. Very un-American!"

The news of Russian missile deployment came the day after U.S. National Security Adviser Michael Flynn resigned following reports he misled Vice President Mike Pence and other officials about his contacts with Russia. Trump was informed Flynn had misled Pence but the president kept his No. 2 in the dark and waited nearly three weeks before ousting the aide.

Asked why Trump kept Flynn, White House Press Secretary Sean Spicer told reporters Tuesday, "The irony of this entire situation is that the president has been incredibly tough on Russia. He continues to raise the issue of Crimea, which the previous administration allowed to be seized by Russia."

Spicer continued, citing a statement from U.S. ambassador to the United Nations Nikki Haley before the U.N. Security Council on her first day denouncing the Russian occupation of Crimea: "As Ambassador Haley said at the time, 'The dire situation in eastern Ukraine is one that demands clear and strong condemnation of Russian actions.'"

Trump tweeted Wednesday, "Crimea was TAKEN by Russia during the Obama Administration. Was Obama too soft on Russia?" He added, "The real scandal here is that classified information is illegally given out by "intelligence" like candy. Very un-American!"

In his first public comments on Flynn's firing, Trump said during a White House news conference with Israel's prime minister Wednesday that it was "really a sad thing that he was treated so badly."

Trump has been critical of numerous foreign leaders while on the campaign trial and after taking office, including U.S. allies Mexican President Enrique Peña Nieto and Germany's leader Angela Merkel. He has refused to explicitly criticize Putin.

Asked by Fox News's Bill O'Reilly earlier this month if he respects Putin, Trump said, "I do respect him, but I respect a lot of people. That doesn't mean I'm going to get along with him."

Trump said he would appreciate any assistance from Russia in the fight against ISIS and would rather get along with Putin.

"But, [Putin] is a killer," O'Reilly said.

"There are a lot of killers," Trump responded, "We've got a lot of killers. What do you think? Our country's so innocent?"

NBC has reached out to the White House for comment on Russia's deployment of a cruise missile and the Russian ship roaming off the U.S. east coast.

The Russian spy ship Vicktor Leonov had made a port call in Cuba prior to moving north, where it has been monitored off the coast of Delaware Tuesday, the official told the AP.

The ship was Wednesday spotted in international waters abut 30 miles south of Groton, Connecticut, Fox News reported, citing a U.S. official.

Business Insider quoted a Defense Department spokeswoman as saying the Pentagon was aware of the vessel.

"It has not entered U.S. territorial waters. We respect freedom of navigation exercised by all nations beyond the territorial sea of a coastal State consistent with international law," Lt. Col. Valerie Henderson told the news organization.

According to the Military Times, the Pentagon said Gen. Joe Dunford will meet with his "Russian counterpart Thursday to discuss military relations & recent close encounters."

The Obama administration three years ago accused the Russians of violating the 1987 Intermediate-Range Nuclear Forces Treaty by developing and testing the prohibited cruise missile, and officials had anticipated that Moscow eventually would deploy it. Russia denies that it has violated the INF treaty.

U.S. intelligence agencies have assessed that the missile became operational late last year, said an administration official, who wasn't authorized to publicly discuss the matter and demanded anonymity.

The deployment may not immediately change the security picture in Europe, but the alleged treaty violation may arise when Defense Secretary Jim Mattis attends his first NATO meeting in Brussels on Wednesday.

NATO Secretary General Jens Stoltenberg said Wednesday that "compliance with arms control agreements is of great importance and especially when it comes to treaties covering nuclear weapons."

He said that "any non-compliance of Russia with the INF Treaty would be a serious concern for the alliance."

The deployment has also stirred concern on Capitol Hill, where Sen. John McCain, the Senate Armed Services Committee chairman, called on the Trump administration to ensure U.S. nuclear forces in Europe are ready.

"Russia's deployment of nuclear-tipped ground-launched cruise missiles in violation of the INF treaty is a significant military threat to U.S. forces in Europe and our NATO allies," McCain, R-Ariz., said in a statement Tuesday. He said Russian President Vladimir Putin was "testing" Trump.

The New York Times, which was first to report the missile deployment, said the Russians have two battalions of the prohibited cruise missile. One is at a missile test site at Kapustin Yar and one was moved in December from the test site to an operational base elsewhere in the country.

The State Department wouldn't confirm the report. It noted that last year it reported Russia was in violation of its treaty obligations not to possess, produce or flight-test a ground-launched cruise missile with a range of between 500 and 5,500 kilometers, or to possess or produce launchers for such missiles.

"The administration is undertaking an extensive review of Russia's ongoing INF treaty violation in order to assess the potential security implications for the United States and its allies and partners," State Department spokesman Mark Toner said.

John Tierney, executive director of the Center for Arms Control and Non-Proliferation, said strategic stability on the European continent is at stake.

"If true, Russia's deployment of an illegal ground-launched cruise missile represents a very troubling development and should be roundly condemned," Tierney said.

Connecticut Democratic Sen. Chris Murphy in a statement Wednesday tied reports about the spy ship, treaty violation, buzzing of the U.S. Navy destroyer and fighting in eastern Ukraine as all part of "a series of aggressive actions."

"Putin clearly thinks the Trump administration has given him a permission slip to flex his muscles," he said. "President Trump and his administration must end their silence and immediately respond to these threats to our national security.”