Ukraine pledged funds on Sunday to try to keep its airspace open to commercial flights, as some carriers reviewed their services to the country after the United States warned that Russia could invade at any time.
Dutch airline KLM - part of Air France - said it would stop services to Ukraine and Germany's Lufthansa said it was considering suspending flights.
Two third of the 298 passengers killed when Malaysia Airlines MH17 was shot down over eastern Ukraine in 2014 as it flew from Amsterdam to Kuala Lumpur were Dutch citizens.
Ukraine's infrastructure ministry said airlines were continuing to operate "without any restrictions", and Prime Minister Denys Shmygal said the government had allocated 16.6 billion hryvnia ($592 million) to guarantee the continuation of flights through its airspace.
He said the funds would "ensure flight safety in Ukraine for insurance and leasing companies."
"This decision will stabilise the situation on the market of passenger air transportation and will guarantee the return to Ukraine of our citizens who are currently abroad," he said, without specifying how the funds would be allocated.
Mykhailo Podolyak, an adviser to the Ukrainian president's chief of staff, earlier said he saw no point closing its airspace in response to Moscow's troop build-up.
Scheduling reconfigurations by individual carriers had "nothing to do with the decisions or policies of our state," he told Reuters.
"The most important point is that Ukraine itself sees no point in closing the sky ... And, in my opinion, that would somewhat resemble a kind of partial blockade."
News agency Interfax Ukraine said Ukrainian insurance companies had received a notification from reinsurers that airlines were not covered for war risks.
Ukrainian carrier SkyUp said it had to divert a flight from Portugal to Ukraine on Saturday after the plane's owner barred it from entering Ukrainian airspace.
SkyUp CEO Dmytro Seroukhov saidthe airline was "working together with state authorities to find solutions."
NO SIGNS OF EXODUS
The United States, its Western allies and other nations have been scaling back or evacuating embassy staff and have advised their citizens not to travel to Ukraine amid the standoff.
Washington says the Russian military, which has more than 100,000 troops massed near Ukraine, could invade at any moment. Moscow denies having any such plan and has described such warnings as "hysteria".
At Kyiv's Borispil Airport, the largest in Ukraine, there was little sign on Saturday of an exodus.
Oksana Yurchenko was travelling back to Australia with her child. "We were visiting our family here in Ukraine. We were planning to stay a bit longer but this situation is a bit scary," the chef and a beauty salon owner said.
Australia has advised its citizens to leave Ukraine and said on Sunday it was evacuating its embassy.
Ricky, a Scotsman who lives in Ukraine, said he saw no sign of public anxiety on the streets. "I do not see anyone in fear in Ukraine, everyone is just getting on with their life," he said at the airport as he waited for a flight to go on holiday.