The same day it agreed to a set of protocols with the US over air activity in Syria, Russia's Defense Ministry uploaded a revealing video of just how close planes above the war-torn country have come.

The ministry released a clip on Tuesday from inside a Russian plane's cockpit as it encountered an American Reaper drone, at one point coming close enough to make out movements of its propeller.

The video, subtly titled 'The intensity of aircraft presence in Syrian air space has grown', shows the Russian pilot maneuver around and under the unmanned MQ-9 drone as his helmet is reflected in the cockpit window.

It came after recent reports that planes from the former Cold War adversaries had come so close that pilots were able to see each other.

The Russian Defense Ministry released a video on Tuesday showing a pilot coming close to an American MQ-9. At one point the fighter plane is so close that it can see the propeller on the unmanned aerial vehicle move

The Russian pilot maneuvers under the American drone as both fly thousands of feet above war-torn Syria

The encounter shows how close aircraft from the two countries are coming over the skies of Syira, though an aviation expert says pilots practice such intercepts. Above, the pilot's helmet reflected in the cockpit

Aviation consultant Stephen Ganyard told ABC that the Defense Ministry footage was 'a controlled intercept, very routine.'

'These are the kinds of intercepts that all fighter pilots practice'.

Information about the Russian plane was not immediately available, though Russian aviation enthusiasts discussing the video believe it is a Sukhoi-30SM.

On Tuesday US officials also said that American pilots have been told not to react to aggressive Russia military aircraft flying above Syria,

The official, who is said to be familiar with recent close encounters, told CNN that pilots have been instructed to proceed with normal aviation safety procedures.

Russian planes have flown extremely close to US planes twice in the past two weeks – one flew within 500ft and another, on Thursday, came within 1,500 feet of two U.S. jets.

However, there was no suggestion of hostile intent or action in either incident.

Today the United States and Russia signed a memorandum of understanding that includes steps their pilots should take in order to avoid inadvertent clashes in the air over Syria as the two countries conduct separate bombing campaigns.

Pentagon press secretary Peter Cook told reporters: ‘With today’s signatures, the memorandum of understanding is now in effect.

‘That was signed a short time ago, earlier today.’

Cook said the full text of the memo would not be released at Russia’s request, but added that it included specific protocols for air crews to follow.

A ground communications link between the two sides will also be established in the event that air communications fail.

Pentagon Press Secretary Peter Cook (pictured in a file photo) told reporters today that a memorandum of understanding between Russia and the US was signed and came into effect today

US pilots have been told not to react to aggressive Russia military aircraft flying above Syria, according to an official. Pictured: a image from the Russian Defense Ministry shows an air strike conducted in Idlib province

A Pentagon spokesman said the full text of the memo would not be released at Russia's request, but that it calls for aircraft to maintain a safe distance. Pictured: a file photo shows a Sukhoi jet like those used in Syria

Cook said the memo calls for aircraft to maintain a safe distance, but he declined to be more specific about whether the protocols included specific distances.

He added that the agreement included coalition aircraft. Coalition members include Saudi Arabia, the United Arab Emirates and Turkey, where Prime Minister Ahmet Davutoglu said that the NATO country had downed a Russian-made drone on Friday.

The Syrian government also uses Russian-made supplies, and Russian officials told Turkey that the drone was theirs.

Despite the agreement between Russia and the US, Cook remained cautious about any endorsement of Russia's bombing campaign against ISIS and rebels opposed to Moscow ally Syrian President Bashar al-Assad.

‘The fact that we have had to resort to a memorandum of understanding gives you an indication of our concern about Russia's activities but (also) our willingness to work with the Russians when it's in our own interest,’ he said.

The US State Department said the agreement is only about keeping pilots safe.

Spokesman John Kirby said: ‘It's not a treaty of cooperation or anything like that ... It doesn't connote cooperation or coordination or joint targeting.’

The issue of aircraft safety started after Russia started bombing targets in Syria last month.

Moscow claims it is attacking Islamic State, but many of its air strikes have hit territory held by other rebel groups fighting against Assad.

State Department spokesman John Kirby (pictured this week) said the agreement is only about keeping pilots safe and is not a 'treaty of cooperation'

Earlier this month, the Pentagon said US-led coalition aircrafts bombing Islamic State in Syria were re-routed at least once to avoid a close encounter with Russian planes.

‘The U.S. and Russia will form a working group to discuss any implementation issues that follow,’ Cook said, during a press briefing.

Meanwhile, Moscow confirmed it had signed the memorandum on preventing mid-air incidents from the US military.

According to RBK, Deputy Defense Minister Anatoly Antonov said: ‘The memorandum contains a number of rules and restrictions aimed at preventing incidents between American and Russian aircraft.’

The report said that Antonov called the agreement a 'positive step' and that it 'spoke to the high potential for cooperation between our two countries, including in the fight against terrorism'.

Russia had asked for ‘deconfliction’ talks with the United States after Moscow began bombing Syria on September 30.