Amid the escalating tensions between the West and Russia, Ms Truss confirmed she is now working with international partners on a set of new sanctions. Speaking in Parliament, Ms Truss also warned Vladimir Putin, the UK will not allow Russia to wage a campaign to subvert its "democratic neighbours". Not only did she threaten Russia with sanctions but warned any military aggression against Ukraine would carry severe consequences for Mr Putin.

       She said: "We will not accept the campaign Russia is waging to subvert its democratic neighbours.

       "They have falsely cast Ukraine as a threat to justify their aggressive stance.

       "The UK is working with our partners on these sanctions, including high impact measures targeting the Russian financial sector and individuals."

       The Ukrainian government estimates there are 100,000 Russian troops on the border.

       Mr Putin has also accused NATO of being an aggressor to Russia, despite annexing the Crimean peninsula from Ukraine in 2014.

       During her speech, Ms Truss also restated the UK's stance against the Nord Stream 2 pipeline.

       Previous German Chancellor, Angela Merkel agreed the Nord Stream 2 project with Russia although the German network agency has stalled on the pipeline's final approval.

       The pipeline will take gas into Germany but bypass Poland, Ukraine and the Baltic states.

       JUST IN: Brexit LIVE: Truss holds talks with Coveney TODAY

       Ms Truss added: "Russia is the aggressor here.

       "NATO has always been a defensive alliance.

       "It's vital that NATO is united in pushing back against Russia threatening behaviour.

       "Europe must reduce its dependence on Russian gas.

       DON'T MISS

       Russian forces deployed in ex-Soviet bloc as violence erupts [Latest]

       Covert Russian troops 'already in Ukraine' warns ex US Navy commander [Update]

       Putin planning nuclear blackmail to recreate USSR on EU border [Insight]

       "Britain remains opposed to Nord Stream 2 and I'm working with allies and partners to highlight the strategic risks of this project."

       Next week Ms Truss will join NATO foreign ministers to discuss the situation with Russia.

       Ahead of the meeting, she said: "Tomorrow I will join an extraordinary meeting of NATO foreign ministers.

       "The US-Russia dialogue begins on Sunday, followed by the Nato-Russia Council on Wednesday, and the OSCE Permanent Council on Thursday.

       "We will be in talks on the basis of freedom, democracy and the rule of law.

       "It's vital that Nato is united in pushing back against Russia's threatening behaviour, and together we must hold Russia to its longstanding obligations.

       "There can be no rewards for aggression. We are reaching a crucial moment."

       As well as annexing Crimea from Ukraine, Russia has backed separatist troops in the Donbass region.