Cruise lines are watching the situation in Ukraine and may change itineraries if necessary.

All four flights scheduled to fly from the UK to Ukraine were canceled on Thursday after the Foreign Office warned of severe disruption.

Boris Johnson, the prime minister, said that Aeroflot will be banned from landing in the UK or flying in UK airspace as part of a series of new sanctions.

The Civil Aviation Authoriry has suspended the foreign carrier permit held by Aeroflot until further notice.

The FCDO had already advised against all non-essential travel to Ukraine and today urged visitors to leave immediately.

P&O Cruises and Cunard both said they may change itineraries.

In light of the current situation in Ukraine, we will amend itineraries as necessary. The safety and wellbeing of guests and crew is of the highest priority and we will advise guests of any changes.

Following the FCDO's update last week, Saga altered its upcoming cruise to the Black Sea, which was due to call at Odessa.

The rest of the cruise is unaffected by the change, according to a spokeswoman.

We are looking at the impact of today's developments on our Baltic cruises which were due to call in at St Petersburg.

We will continue to monitor the situation and if necessary make further alterations to our itineraries whilst still ensuring the best experience for our guests.

Russia cruises are planned for later this year by Riviera Travel. The company is currently monitoring the situation and will provide updates when possible, according to a spokesman.

The Baltic itineraries have been adjusted because of the invasion.

The World Navigator ship has dropped St Petersburg from its itineraries.

The ship will leave on September 7 and call at both Mariehamn and Kotka in Finland.

The safety and comfort of our guests and crew is our top priority, according to the president of the line.

Guests will enjoy these unique and rarely visited destinations and shore excursions to take in the rich cultures and breath-taking vistas of the Baltic.

There is a picture credit of Maykova Galina.