White House national security adviser Jake Sullivan gives an update about Ukraine during a press briefing at the White House, Friday, Feb. 11, 2022, in Washington. AP
Belgium joins the US and several European countries, who have called on their citizens in Ukraine to leave the country for fear war breaks out.
"Nationals who are currently in Ukraine and whose presence is not strictly necessary in the country are strongly advised to leave the country," the Belgian foreign ministry said on its website.
It said it strongly advised against travel to the country, adding that an evacuation could not be guaranteed.
The ministry said that in case of a "sudden deterioration, communication links including internet and telephone lines could be seriously affected" and air links hampered.
White House National Security Advisor Jake Sullivan told reporters in Washington on Friday that an attack by the more than 100,000 Russian troops currently massed next to Ukraine "could occur any day now" and said Americans in Ukraine "should leave as soon as possible."
The European Union has told non-essential staff from its diplomatic mission in Ukraine to leave the country but has not issued an evacuation order.
Several EU countries have also asked their nationals to leave Ukraine, notably Estonia and Lithuania.