Liz Truss is set to tell her foreign counterparts that the “age of engagement with Russia is over” and declare that an agreement between Nato and Moscow which said the two sides “do not consider each other as adversaries” is dead.

The Foreign Secretary will attend a working dinner with Nato counterparts in Brussels on Wednesday evening, where she is expected to say the defensive alliance must toughen its response and not allow security vacuums to emerge.

She is expected to say: “The age of engagement with Russia is over. We need a new approach to security in Europe based on resilience, defence and deterrence. There is no time for false comfort. Russia is not retreating, but regrouping and repositioning to push harder in the east and south of Ukraine.”

Ms Truss is expected to push the importance of continuing to arm Ukraine, and toughening up sanctions, as the UK announced more measures on Wednesday.

Asset freezes have been imposed on Sberbank, Russia’s largest bank, and the Credit Bank of Moscow.

All new outward investment to Russia has been banned and the UK has also committed to end all imports of Russian coal and oil by the end of the year, with gas to follow as soon as possible.

Imports of Russian iron and steel products will be banned and a further eight oligarchs have also been added to the sanctions list.

Ms Truss said they are “some of our toughest sanctions yet”.

At the Nato meeting, Ms Truss is also expected to urge more support for countries such as Georgia, Moldova, Sweden, and Finland.

She is also expected to say the Nato-Russia Founding Act, in which it was declared the two sides “do not consider each other as adversaries”, is dead.

The agreement, signed in 1997, aimed to increase security and stability.