The corresponding order was issued on the eve of Boris Johnson’s visit to Brussels and Warsaw.

The British authorities have ordered 1,000 troops to prepare to provide support in the event of a humanitarian crisis caused by any kind of Russian aggression against Ukraine. The corresponding order was made on the eve of Prime Minister Boris Johnson’s visit to NATO headquarters and to the Polish capital.

Johnson will travel to Brussels and Warsaw on Thursday to stress the need to adhere firmly to NATO principles and discuss with allies what military support the UK can provide while Russia gathers its troops near the border with Ukraine.

Earlier this week, French President Emmanuel Macron met with Russian President Vladimir Putin. Vice President Kamala Harris will personally meet with the allies and partners of the United States at the Munich Security Conference next week.

The British Foreign Minister and Defence Minister are due to arrive in Moscow this week for talks.

“The UK remains unwavering in its commitment to European security,” Johnson said in a statement. “As an alliance, we must state our position and clearly state the existence of principles according to which we will not compromise.”

On Monday, Britain said it would send 350 more troops to Poland after 100 British soldiers were sent to the Eastern European country last year to help with the migration crisis on the border with Belarus.

On Wednesday, Johnson’s office reiterated that any further Russian military incursion into Ukraine would likely lead to massive forced displacement of people inside Europe, affecting countries such as Poland and Lithuania. In 2014, Russia annexed the Crimean Peninsula from Ukraine.

Johnson’s office said that the Prime minister will also discuss with NATO Chief Jens Stoltenberg the UK’s proposal to strengthen the alliance’s defense, including doubling the number of troops in Estonia, increasing the number of British Air Force fighters in Southern Europe, as well as sending patrol ships and destroyers with guided missile weapons to the Eastern Mediterranean.