Originally Published: 13 MAY 22 12:01 ET

Updated: 13 MAY 22 13:33 ET

By Oren Liebermann, CNN

(CNN) -- US Secretary of Defense Lloyd Austin spoke with his Russian counterpart for the first time since the Russian invasion of Ukraine, the Pentagon announced on Friday.

The call lasted approximately an hour and was at the request of Austin, who used the first call between the two in 84 days to urge Defense Minister Sergei Shoigu to implement an "immediate ceasefire," according to a brief readout of the call. The two last spoke on February 18, a week before Russia launched its invasion of Ukraine.

It ends an extended period in which Russia's top military leaders repeatedly refused to speak with their American counterparts.

On March 24, Pentagon press secretary John Kirby said that Austin and Joint Chiefs Chairman Gen. Mark Milley "have sought, and continue to seek" phone calls with Shoigu and the Gen. Valery Gerasimov, the top Russian general, but the Russians "have so far declined to engage."

Following the call between Austin and Shoigu, Milley is also expected to reach out to his Russian counterpart to see if it's possible to schedule a call, a defense official tells CNN, but there is no conversation currently on the schedule.

The two have not spoken since February 11, one week before the last call between Austin and Shoigu.

On March 1, the US and Russia established a deconfliction line because the two militaries are operating so close together. Some of Russia's strikes in Ukraine were close to the border with Poland where US troops are operating. Similar to the deconfliction mechanism the US and Russia have over Syria, the idea is to avoid any miscalculation or misunderstanding that might lead to an unintentional and dangerous escalation.

But even as the Pentagon said the line was successfully tested once or twice daily, there was no communication until now at the highest levels of the US and Russian militaries.

"We have not stopped trying [to establish communications] since the last time they spoke, which is right before the invasion, so it's been a consistent effort," a senior defense official said in a briefing with reporters Friday.

But the official tempered expectations on the impact of the call, saying it wouldn't solve any "acute issues" or result in "direct change" in Russia's military actions or increasingly hostile rhetoric.