Several airlines are reviewing their flight links to Ukraine, with some canceling connections altogether, news wire Reuters reports.
Dutch airline KLM, owned by AirFrance, says it will halt all Ukraine flights, while German carrier Lufthansa says it is considering the same move, Reuters says.
One Portuguese-owned airline, SkyUp, had diverted a plane destined for Kyiv, on the airline's orders.
Ukrainian authorities so far have said that they see no reason to close national airspace amid the continued build-up of Russian military forces on the country's borders.
Unconfirmed reports stated that the government may be discussing the issue Sunday.
Australia has advised its citizens to leave the country and said Sunday it is evacuating its embassy, while the U.S. and U.K. have issued recommendations that their citizens also leave or not travel to Ukraine.
Reuters reported no sign of any mass exodus at the largest airport in the country, Borispil Airport in Kyiv, with only individual citizens who reside abroad flying out after visiting family, for instance.
An advisor to Ukraine's President Volodymyr Zelensky said that the halting of flights was a decision for the airlines and was not official government policy, and would in fact be tantamount to a blockade were authorities to do so.
The government of Ukraine is reportedly also looking at ways to compensate airlines who may encounter problems with their insurers, one source told Reuters, on the basis that airlines may well not be covered for war risk.
The original Reuters piece is here.
Multiple sources have stated that well over 100,000 Russian military personnel are massed on the Russian side of the border with Ukraine, while Washington says that the large number of forces could potentially make an incursion at any time in the next few days.
The Kremlin has rejected such rumors as scare-mongering.
The July 2014 downing of Malaysia Airlines Flight 17, thought to be caused by a BUK surface-to-air missile fired from a system provided by Russia to pro-Russian separatists in eastern Ukraine, caused the deaths of 298 people.
Estonia's foreign ministry said Friday evening that any of its citizens in Ukraine should return home immediately, while "non-essential travel" should be avoided.
Editor: Andrew Whyte