Aircraft flying to or from UK airports are being ordered to avoid Ukraine airspace after the crisis in the country intensified.
Transport Secretary Grant Shapps said he made the decision “following the horrific events overnight” as Russia launched a major military assault.
The Cabinet minister tweeted: “I’ve instructed @UK_CAA (the Civil Aviation Authority) to ensure airlines avoid Ukraine airspace to keep passengers and crew safe.
“We continue to stand with the people of Ukraine and work with our international partners to respond to this act of aggression.”
This is affecting UK flights to and from Ukraine airports, and which were due to fly over the country.
Wizz Air cancelled its flights between Luton Airport and the Ukrainian cities of Kyiv and Lviv on Thursday.
The Hungarian airline told passengers: “Due to the current events in Ukraine and the airspace closure, Wizz Air must temporarily suspend all flights to and from the country.”
Ryanair and Ukraine International Airlines – the other carriers which fly between the UK and Ukraine – are also expected to suspend those routes.
The lack of flights will make it harder for British nationals to evacuate from Ukraine to the UK.
The Foreign Office updated its travel advice to state: “Ukraine’s airspace is closed. It is likely that commercial routes out of Ukraine will be severely disrupted and roads across Ukraine could be closed.”
It added: “Russia’s military action in Ukraine will severely affect the British Government’s ability to provide consular assistance in Ukraine.
“British nationals should not expect increased consular support or help with evacuating in these circumstances.”
On Tuesday, Foreign Secretary Liz Truss urged Britons in the country to “leave now via commercial routes while they are still available”.