TEHRAN: Iran called for a "political and democratic" solution after Russia launched an invasion of Ukraine on Thursday in a crisis the Islamic republic accused NATO of provoking.

"We don't believe that resorting to war is a solution," Iran's Foreign Minister Hossein Amir-Abdollahian tweeted.

It was "imperative to establish (a) ceasefire" and "find a political and democratic resolution", he added.

His post came after Russia hit military facilities across Ukraine with air strikes before sending in ground forces.

Amir-Abdollahian reiterated an assertion by Iran that NATO and the United States were to blame for the escalation.

"The Ukraine crisis is rooted in NATO's provocations," he added.

The foreign ministry said Iran was working to evacuate its citizens from Ukraine, which closed its airspace early on Thursday.

More than 40 Ukraine soldiers, nearly 10 civilians killed

"We are in contact with both sides and we emphasised that the security of our compatriots is a priority for us," its spokesman Saeed Khatibzadeh told state TV.

About 4,000 Iranians live in Ukraine, according to the latest foreign ministry figures.

The Iranian embassy in Kyiv has asked all Iranians in the country to leave in "any way possible".

"If the conditions for leaving Ukraine are not met, we urge people to settle in safe havens and shelters provided by city and provincial authorities," it said in a statement.