Vladimir Putin’s message of congratulations to Donald Trump was already trying to get in his head to “manipulate” him, says a former MI6 chief.

Sir Alex Younger, who headed the British Secret Intelligence Service from 2014 to 2020, described the words to the US president elect from former KGB man Putin as “classic spy bluster”.

The Russian president on Thursday congratulated Trump on winning the US election, praised him as a “real man” in the way he acted “courageously” when a gunman tried to assassinate him, and said Moscow was ready for dialogue with him.

Sir Alex, who was known as “C’ as Britain’s spy chief, stressed that these words would have been very carefully chosen.

“This is classic spy bluster…I should know,” he told BBC radio.

“Putin has access to the best psychologists and would have thought very carefully about how to send the most manipulative and flattering message he can manage.”

He believes Putin will be “very pleased” with Trump’s victory over Democrat Kamala Harris.

“But I think also he knows there is a lot in play here,” Sir Alex added.

“There is a real risk that he overreaches and there is a reference in the early report about Trump’s unpredictability.

“Putin is a tactical opportunist, that is kind of what spies are like.

“But strategically, actually he has sent some very mixed messages about what is going to happen next.”

In his first public remarks since Trump’s win, Putin highlighted how the Republican property tycoon responded when he was shot while speaking at a campaign rally in Pennsylvania in July.

“He behaved, in my opinion, in a very correct way, courageously, like a real man,” Putin said on a visit to the Russian Black Sea resort of Sochi.

“I take this opportunity to congratulate him on his election.”

On Trump’s claim that he could swiftly end the Ukraine war, the Russian president added: “What was said about the desire to restore relations with Russia, to bring about the end of the Ukrainian crisis, in my opinion this deserves attention at least.”

Putin, 72, appeared to acknowledge that Trump, 78, was unpredictable, with his rhetoric often not matching his actions.

“I do not know what is going to happen now. I have no clue,” he added, signalling that he was ready for talks with Trump.

Sir Alex stressed the need to be “open-minded” given the reality of what is happening in Ukraine and that the previous policy which he described as “letting Ukraine lose slowly” was not “working very well”.

He expects Trump to seek a quick resolution of the conflict but said he is “being pulled in two directions”.

Some of Trump’s advisers were arguing that Ukraine should be forced into unarmed neutrality and giving up territory which meant “back into the bosom of Putin” while others supported a land swap but also reinforcing Kyiv’s military and economic capabilities, though possibly short of Nato membership.

“We need to make sure we are compounding that second argument,” Sir Alex emphasised.

The first option of loss of territory and unarmed neutrality for Ukraine would “embolden Putin to a degree that makes Europe’s position highly perilous,” added Sir Alex.

But he believes Trump can be persuaded to reject such a policy given the risk of it meaning that he ends up “owning a fiasco”.

He described Trump as “disdainful” of alliances, having previously threatened to scale back support for Nato, and so Europe could no longer rely on a defence system, heavily reliant on America, set up after the Second World War

“If Europe does not smell the coffee now and understand it needs to work to own its own security then frankly we will not be forgiven by future generations,” stressed Sir Alex.

He rebuffed claims that a second Trump administration will hit US-UK intelligence ties, saying they were stronger at the end of his first term in the White House than at the start.