A Russian spy ship on the edge of UK waters has used lasers for the first time to disrupt RAF pilots monitoring its activities, the defence secretary has said.

John Healey told a press conference in Downing Street the government was taking the “deeply dangerous” move “extremely seriously”.

He added that the vessel, named Yantar, was north of Scotland and had entered UK waters over the last few weeks, for the second time this year.

The ship is “designed for gathering intelligence and mapping our undersea cables”, Healey told journalists.

“My message to Russia and to Putin is this: we see you. We know what you’re doing. And if the Yantar travels south this week, we are ready,” he added.

Giving more details on the vessel, Healey said: “It is part of a Russian fleet designed to put and hold our undersea infrastructure and those of our allies at risk.

“It isn’t just a naval operation. It’s part of a Russian programme driven by what they call the Main Directorate of Deep-Sea Research, or GUGI, and this is designed to have capabilities which can undertake surveillance in peacetime and sabotage in conflict.

“That is why we’ve been determined, whenever the Yantar comes into British wider waters, we track it, we deter it and we say to Putin we are ready, and we do that alongside allies.”

He said this was a demonstration of Britain’s capability and “readiness to act”.

The defence secretary issued a warning in January about the ship after it was spotted in UK waters.

At his Downing Street press conference, he said this was the first time Yantar had used lasers in an effort to “disrupt” RAF pilots, which he described as a “deeply dangerous” and something the UK took “very seriously”.

He said he had changed the Royal Navy’s rules of engagement so that it could follow the Yantar more closely “when it’s in our wider waters”.

“We have military options ready should the Yantar change course. I am not going to reveal those because that only makes President Putin wiser,” he said.

The UK and its Nato allies are concerned about the risk Russia poses to offshore cables, pipelines and other infrastructure critical to internet connectivity.

In his speech, the defence secretary warned about Russian incursions into Nato airspace, as well as the threats posed by China and armed conflicts around the world, adding: “Our world is changing. It is less predictable. It is more dangerous.”

The Ministry of Defence has come under criticism from a committee of MPs for being over-reliant on US defence resources and not being prepared to defend the UK and its overseas territories from military attack.

The committee said the UK and its European allies should be building up their capabilities to prepare for potential US withdrawal.

Healey said the UK government “takes a different view” to the committee about America’s commitment to Nato.

“The strength of Nato is not just about the defence of Europe. it’s about the defence of America too,” he told reporters.

But he said the committee was “right to say” Britain should “pick up the pace of our commitment” and that was something Labour has been doing since it came to power last year.

The report comes as British negotiators race to agree a deal with the EU to enable British defence companies to contribute to projects funded by a new €150bn (£130bn) EU defence loan scheme set to launch next year.

The Labour government wants to conclude a deal in the coming weeks to allow British companies to take part in the first round of bids from EU countries, with applications due by the end of this month.

Healey told reporters the UK wanted to be part of the programme, but not “at any price”, amid reports the two sides are at odds over the entry fee the UK could pay to enable British firms to take part.

He added that any financial contribution to take part would have to be “good value for money for our taxpayers and our industry”.