Britain warned Russia on Wednesday that it was ready to deal with any incursion into its territory after a “spy” ship was detected on the edge of U.K. waters north of Scotland.

UK secretary of state for defence John Healey said the Russian vessel had directed light lasers at British pilots sent to monitor its activities.

He added that a Royal Navy frigate and RAF P-8 planes have been deployed to monitor and track the vessel’s every move.

Healey said during a speech in London on Wednesday that the spy ship entered the UK’s wider waters over the last few weeks (between 5 and 11 November).

“This is a vessel used for gathering intelligence and mapping undersea cables,” the defence secretary noted.

“My message to Russia and to Putin, is this: We see you. We know what you are doing.”

Healey condemned the “deeply dangerous action” by Russia and said the UK had military options ready if the ship travels south this week. It is the second time the vessel has entered British waters in the last year.

“And I want to praise the dedicated and professionalism of our armed forces. They work 24/7, 365 days a year to keep our nation safe.”

The defence secretary revealed the news as he warned the UK needs to step up its defences in a “new era of hard power.” He said: “This is also stark reminder that we are in a new era of threat. Our world is changing. It is less predictable, more dangerous.

“In the past year alone, we’ve seen: the Iran-Israel war drag the Middle East close to the brink; armed conflict break out between India and Pakistan; Chinese spies targeting our democracy at home; Putin escalate still further his war in Ukraine; and just this last year we have also seen Europe’s skies plagued by drone disruptions; we’ve seen Russian incursions into NATO airspace double and we’ve seen 90,000 cyber-attacks on the UK Defence system alone.

“This is a new era of threat it demands a new era for defence. An era of hard power, strong allies and sure diplomacy. And as the threat grows, Britain must step up. And we are.”

The Russian embassy to the UK in a statement accused the British government of being “Russophobic” and “stoking of militaristic hysteria,” adding that Moscow has no interest in British undersea cables and that the ship is a Russian “oceanographic research vessel operating in international waters.”

“We have taken note of the latest provocative statements by UK Defence Secretary John Healy. The British leadership’s endless accusations and suspicions only cause a smile. Russia’s actions do not impinge upon the interests of the United Kingdom, nor are they intended to undermine its security,” an embassy spokesperson said.