All British nationals in Ukraine should leave the country immediate, says the UK government.
The British Foreign Office says "British nationals in Ukraine should leave now while commercial means are still available."
Norway's government has issued the same advice, calling for all Norwegians to leave Ukraine immediately "due to a serious and unpredictable situation" in the country.
Yesterday US President Joe Biden urged all American citizens to leave the country, warning that "things could go crazy quickly."
What should British citizens in Ukraine do?
According to the UK Foreign, Commonwealth and Development Office (FCDO), British nationals should look to use commercial means to leave Ukraine.
The British embassy is still open, however will not be able to provide in-person consular assistance.
"British Nationals should not expect increased consular support of help with evacuating in these circumstances," says a notice from the Foreign Office.
However, the FCDO is asking British citizens in Ukraine to register their presence, so they can be provided with the latest information.
This can be done here.
What should Norwegian citizens in Ukraine do?
The Norwegian Ministry of Foreign Affairs is advising all citizens to leave Ukraine immediately. It has cautioned against travelling closer than 250km of the Ukrainian/Russian border.
The Ministry also advises against all travel to Belarus, apart from the capital city Minsk.
Currently, Norwegian citizens in Ukraine are being advised to contact their insurance provider for practical help. The government is asking Norwegian nationals to use commercial exit routes at the moment.
According to a statement on the government website, should the security situation deteriorate, "the Foreign Service will have a limited opportunity to help Norwegian citizens in these areas."
The government is also asking Norwegians in Ukraine to register on the Reiseklar app so authorities can send further information.
Which other countries have advised against travel to Ukraine?
Earlier today the Dutch government advised citizens to leave Ukraine as soon as possible. The Netherlands also moved its diplomatic post from Kyiv to Lviv for security reasons.
Japan has also urged all nationals to evacuate from Ukraine and avoid travel immediately, "regardless of purposes."
The Latvian government has similarly advised citizens not to travel to Ukraine, due to the ongoing safety concerns.