Deep inside a reinforced bunker in north-western Germany, a dozen Nato air force troops bustle around computers set up in front of a huge screen showing a map of eastern Europe’s airspace.

About 30 green dots, representing Nato planes, cluster the skies on the alliance’s eastern flank bordering Russia, Belarus and Ukraine. The mix of fighter jets, reconnaissance aircraft and support planes are both a show of strength aimed at deterring potential aggression from Moscow, and operations gathering intelligence on the war in Ukraine which could be fed back to Kyiv.

“There’s mountains of data,” said a Nato defence official. “They’re listening, they’re watching.”

Nato’s Combined Air Operations Centre in Uedem, close to the Dutch border, co-ordinates all alliance air operations north of the Alps. It oversees an airborne presence that during peacetime revolves mainly around protecting Nato’s skies from potential incursions, but since the invasion by Russia almost six weeks ago has expanded in size and objectives.

Much like the supply of weapons to Ukraine by Nato members, the flow of military intelligence gleaned from air operations mainly along the Poland-Ukraine border is highly sensitive.

The alliance itself stresses that it is not involved with the co-ordination or dissemination of any intelligence-sharing with Kyiv, but that member states could be taking unilateral decisions to pass on any information that could help Ukraine’s armed forces with their defence.

“It’s up to the nations to decide what they do with that information,” said Major General Harold Van Pee, commander of the Uedem site. “Some nations will probably share some of that information . . . with other interested parties, let’s put it that way.”

US officials have confirmed Washington shares intelligence with Kyiv, but it is not providing data that would enable “real-time targeting” of Russian targets.

Nato owns and operates more than a dozen Boeing E-3A radar planes, with about six of its long-range “eyes in the sky” craft in the air at any time.

They form part of about 100 Nato planes flown each day as part of the alliance’s expanded presence in eastern Europe since the start of the war in Ukraine. This includes fighter jets and manned and unmanned intelligence aircraft operated by individual member countries.

Jens Stoltenberg, Nato secretary-general, said the alliance was “monitoring very closely” events in Ukraine, adding that it had “surveillance capabilities that provide us with a lot of information”.

“Information, and best possible situational awareness is of course extremely critical in such a dangerous situation as we see in Ukraine now,” he told reporters in Brussels on Tuesday.

Van Pee, the Uedem commander, said: “Of course we look into the other side of the border . . . on a real-time basis we want to know what’s flying around over there.”

The expanded Nato air force operations come alongside a wider increase of land and sea deployments in eastern European member states, as the US-led alliance adjusts its defence posture following Russia’s invasion.

An increase in the size of existing deployments and decisions to set up new command structures mean 40,000 troops are now under Nato command on the alliance’s eastern flank, with battle groups set up in all member states bordering Russia, Ukraine or on the Black Sea.

In addition, naval carrier strike groups have been positioned in the North Sea and eastern Mediterranean, with more than 140 ships at sea. US-built Patriot air and missile defence batteries with the ability to shoot down enemy aircraft or missiles have been deployed in southern Poland and Slovakia.

Nato airspace bordering Russia is monitored around the clock at the Uedem site by about 75 multinational troops, who can then order fighter jets based at alliance airfields to scramble and intercept potentially hostile aircraft.

During a visit by journalists on Tuesday, the command centre scrambled an F-35 jet from Norway to monitor a Russian intelligence aircraft that was flying off the country’s northern coast.

In the weeks since the invasion Uedem has noted an increase in these high-alert “Alpha” scrambles from a normal rate of about one every other day, which officials at Uedem attribute to a combination of higher Russian activity and heightened Nato sensitivity.

“We’ve not seen any successful attempts,” Van Pee said of Russian incursions into Nato’s airspace, adding, “We know how to counter those things.”

Uedem’s control bunker can also spot and track cruise missiles, such as those fired by Russia that recently hit a military training base in western Ukraine previously used by Nato.

That attack last month, officials at Uedem say, was a real-life example of how the defence, deterrence and surveillance aspects of Nato’s increased air presence in eastern Europe coexist. If they had crossed into Poland — the border is only 12km away — they could have been shot down.

“The farther you can look into the other side, the more warning you get about what eventually might be coming your way,” Van Pee said.