A Russian Su-27 jet flew dangerously close to a U.S. reconnaissance plane over the Pacific northeast recently in an aerial clash not seen since the Cold War.

An Air Force RC-135 electronic intelligence jet was flying a surveillance run some 60 miles off the Russian Far East coast, north of Japan, on April 23 when the incident occurred, according to defense officials familiar with the incident.

The Su-27 flew to follow the RC-135, and at one point rolled sideways to reveal its air-to-air missile before flying within 100 feet of the cockpit in an attempt to unnerve the crew.

The showdown was video-recorded by the aircrew.

Pentagon spokesman Col. Steven Warren said the Su-27 intercepted the RC-135U as it conducted a routine surveillance mission in international airspace over the Sea of Okhotsk during the afternoon of April 23.

"The Su-27 approached the RC-135U and crossed the nose of the U.S. aircraft within approximately 100 feet," Warren told the Free Beacon in a brief statement. "Senior department leaders have communicated our concerns directly to the Russian military."

A defense official said the incident was a "reckless intercept" and one of the most dangerous aerial encounters for a U.S. reconnaissance aircraft since the Cold War.

The RC-135 flight was part of Air Force efforts to increase regional spying under the U.S. pivot to Asia. Last month, two Global Hawk drones were deployed to Japan for spy missions in the region. Other electronic spy aircraft also have increased flights in recent weeks.

The RC-135U is code named "Combat Sent" and specifically collects electronic intelligence from radar emissions. The surveillance flight was collecting data on the increasingly-capable air defense systems in the region. A normal crew for the aircraft includes two pilots, two navigators, three systems engineers, 10 electronic warfare officers and six area specialists.

Retired Air Force Lt. Gen. Thomas McInerney, a former commander in Alaska, voiced concerns about the provocative Russian action.

"The dangerous intercept by a Russian Su-27 is far worse than we experienced during the Cold War," McInerney told the Washington Free Beacon. "In my four plus years as the Alaskan [North American Aerospace Defense] region commander at the height of the Cold War, we never saw such recklessness by the USSR."

McInerney added: "President Putin sees weakness in the current American leadership and is trying to intimidate us. It apparently does not bother this administration."

The U.S.-Russian aerial close call came two days after Japanese warplanes intercepted two Russian military aircraft conducting anti-submarine patrols near Japan’s northern island of Hokkaido.

Kenneth deGraffenreid, former White House intelligence adviser during the Reagan administration, said the aerial encounter could have turned deadly, based on Moscow’s history of using force in illegal actions against aircraft transiting international airspace.

According to deGraffenreid, the Russians since the late 1940s have shot down 70 U.S. aircraft. That figure includes the Russian shoot down of Korean Air Lines Flight 007 in 1983, killing all 269 passengers.

"This has been Russian policy for over 70 years and the Russians are reverting to a very deadly and ugly practice of the Cold War," he said.

Disclosure of the U.S.-Russian aerial faceoff comes as the Obama administration last week approved Russia’s use of upgraded sensors on aircraft used to overfly sensitive U.S. and allied military installations in Europe under the 1992 Open Skies Treaty.

"After careful consideration the United States has decided to certify the electro-optical sensor for the Russian Federation’s AN-30 Open Skies Treaty aircraft, which is used in Open Skies flights over Europe," the administration said in a statement.

The upgraded sensors were opposed by Congress and U.S. military and intelligence officials over concerns the new equipment will increase the national security risk posed by Russian aerial spying.

The certification, under consideration for the past several months, is the latest round in a battle between House Republicans and the administration over the Russian spy flights.

The fiscal 2015 defense authorization bill contains a provision that would prohibit using any funds to certify the upgraded Russian aircraft sensors.

The provision blocks certification unless the Pentagon and intelligence leaders certify to Congress that the digital equipment "will not enhance the capability or potential of the Russian Federation to gather intelligence that poses an unacceptable risk to the national security of the United States."

It also would link new equipment approval under Open Skies to a requirement that Russia is no longer illegally occupying Ukrainian territory and is no longer violating the 1987 Intermediate-range Nuclear Forces Treaty.

"The committee is committed to effective and complete compliance with the Treaty on Open Skies, provided such compliance is not allowed to become a threat to the national security of the United States," the bill says.

The White House, in a statement of policy, said it "strongly objects" to the congressional restrictions.

"This limitation would infringe on the ability of the United States to implement its rights and obligations under the treaty," the Office of Management and Budget said May 19. "A prohibition on U.S. participation in certification procedures would prevent the United States from reviewing, examining, or raising concerns regarding a proposed Russian aircraft or sensor."

"The administration should immediately reconsider this decision which benefits Russia, not the United States or our allies," Rep. Mike Rogers (R., Mich.), chairman of the House Permanent Select Committee on Intelligence, told the Free Beacon. "It is careless for the administration to approve Russia’s request for a sensor upgrade given that country’s recent record and its compliance issues."

Four members of the Senate Select Committee on Intelligence—two Republicans and two Democrats—also expressed opposition to the sensor upgrade. The senators wrote to Secretary of State John Kerry earlier this year urging him to "carefully evaluate the ramifications of certification on future Open Skies observation flights."

The Russian invasion of Crimea and other efforts to destabilize Ukraine are "sufficient enough to counsel further review, irrespective of any technical concerns that may exist," the senators said. It was signed by Republicans Dan Coats of Indiana and James E. Risch of Idaho, and Democrats Mark Warner of Virginia and Martin Heinrich of New Mexico.

"Sen. Coats is very disappointed that the administration chose to rapidly approve the new Russian capabilities so soon after the invasion of Crimea and Moscow’s efforts to destabilize Ukraine, particularly given the concerns of key American stakeholders," said Coats’ spokesman Matt Lahr.

Risch also said he opposed the certification "until Russia becomes fully compliant with their other treaty obligations and is no longer illegally occupying Ukrainian territory."

"Allowing the Russians to upgrade this sensor at this time does not illustrate strength or resolve to President Putin," Risch said through a spokeswoman.

A Defense Science Board task force published in January said upgrading U.S. Open Skies aircraft would be a waste of money, even though Russia is upgrading its aircraft.

"The sensor specifications permitted by the treaty are outdated when compared with the need," the report said. "In fact, the existing treaty requirements can be fulfilled by sensor information readily available from commercial imagery without the expense of flight missions or sensor upgrades."

The State Department, the agency leading the Obama administration’s arm control-centered agenda, pushed for the aircraft certification in a bid to protect the treaty, even though Russia has violated several of its provisions.

A 2013 State Department report on arms compliance said the Russians are violating the Open Skies treaty by restricting spy flights over parts of Moscow, Chechnya, and near the Russian border with Georgia. The Russians also closed airfields and failed to provide proper film in violation of the treaty.

The White House said in a statement that the certification would allow the switch from film to digital photography.

"All states parties agree that the transition from film cameras to digital sensors is required for the long-term viability of the treaty," the statement said.

Said John Bolton, former undersecretary of state for arms control: "Especially in light of Moscow's aggression in Ukraine, the last thing we should be doing is indulging in the illusion of Russia honoring its arms control agreements."

Mark Schneider, a former Pentagon strategic nuclear policymaker, added that he has never regarded the Open Skies accord as important. "But right now we ought to be thinking about deterrence, not playing arms control games," he said.

The Russian violation of international airspace contrasts sharply with the Obama administration’s insistence on pursuing legal international arms agreements with Russia as a way to win Moscow’s favor, said deGraffenreid, the former White House intelligence adviser.

"They are cheating on arms control agreements so how can we trust them when they are interfering with aircraft in international airspace in violation of international law?" he asked. "If we can’t trust them on that, there is no ground for cooperation."

The treaty, signed by 34 nations, is a confidence-building measure that allows legal spying on military sites. "It contributes to European security by providing images and information on Russian forces, and by permitting observation flights to verify compliance with arms control agreements," the White House statement said.

The treaty permits flights using four types of sensors: optical panoramic and framing cameras, video cameras with real-time display, infrared line-scanning devices, and sideways-looking synthetic aperture radar.