Prime Minister Narendra Modi on Thursday called Russian President Vladimir Putin and urged an end to violence in Ukraine, a government statement said on Thursday.

"(The) Prime Minister appealed for an immediate cessation of violence, and called for concerted efforts from all sides to return to the path of diplomatic negotiations and dialogue," the statement said.

Modi also raised the issue of the safety of Indian citizens in Ukraine, especially students, the statement added.

"The prime minister has conveyed ... that the topmost priority of the government is the safety and security of Indian nationals, including Indian students, and their evacuation from Ukraine," Shringla said.

The leaders agreed that their officials and diplomatic teams would continue to maintain regular contacts on issues of topical interest," the statement added.

Meanwhile, India is focusing on evacuating its 16,000 nationals still stuck in Ukraine, Foreign Secretary Harsh Vardhan Shringla said late on Thursday, after Russian forces mounted a mass assault by land, air, and sea on the former Soviet republic.

Teams of Indian foreign ministry officials have been sent to Ukraine's land borders with Hungary, Poland, Slovakia and Romania to provide assistance to any fleeing Indian nationals, Shringla told a press briefing.

Around 4,000 Indians have already been evacuated since the government set up repatriation efforts a month ago, he added.

Indian government advisories call on Indians to find shelter or if possible to attempt to leave the country by land, he said, after Ukraine shut its airspace and evacuation flights were suspended.