Blaise Metreweli, the first woman to lead the MI6 Secret Intelligence Service (SIS), is due to speak at its London headquarters, warning about the "threat" posed by an "aggressive, expansionist and revisionist" Russia, the UK's foreign ministry said in a preview.

"The export of chaos is a feature not a bug in the Russian approach to international engagement, and we should be ready for this to continue until Putin is forced to change his calculus," Metreweli will say, according to extracts released by the Foreign Office.

Metreweli was appointed in June as the 18th head of the service. The MI6 chief is the only publicly named member of the organisation and reports directly to the foreign minister.

She will warn of the increasingly complex nature of global threats and say the "front line is everywhere" as a result of cyber disruption, hybrid warfare, "terrorism and information manipulation".

The new head of Britain's armed forces, Richard Knighton will call for "national resilience" in another speech later on Monday at the Royal United Services Institute (RUSI), a think tank specialising in defence.

"The situation is more dangerous than I have known during my career and the response requires more than simply strengthening our armed forces," the chief of defence staff will say, according to a Ministry of Defence (MoD) statement.

"A new era for defence doesn't just mean our military and government stepping up -- as we are -- it means our whole nation stepping up."

Knighton will announce pound50 million ($67 million) in funding for new "Defence Technical Excellence Colleges" to help defence employers train up staff.

The speeches come as Prime Minister Keir Starmer is due in Berlin later Monday for talks with Ukrainian President Volodymyr Zelensky and European leaders on how to end Moscow's nearly four-year invasion.

Britain has repeatedly warned of the threat from Russia, recently raising the alarm after the government said a Russian military ship was sighted near British waters.

The MoD has just launched a new organisation -- the Military Intelligence Services -- to unify intelligence gathering and sharing efforts undertaken by the army, navy and air force.

"The announcement comes amid escalating threats to the UK, as adversaries intensify cyber-attacks, disrupt satellites, threaten global shipping lanes, and spread disinformation," the MoD said on Friday.