A Japanese expert on foreign relations says growing tensions in eastern Ukraine is highly likely a signal of Russia's desire to have the United States and its European allies come to the negotiating table.

Abiru Taisuke of the Sasakawa Peace Foundation, who is well versed in Russia's diplomacy and security policy, also says a scenario of a Russian invasion of Ukraine is difficult to imagine.

As a reason for his view, Abiru says Russian President Vladimir Putin is expected to hold a meeting with US President Joe Biden, following the one with French President Emmanuel Macron. Abiru says Putin is showing his willingness to continue talks.

At the upcoming US-Russia summit, he says the US won't be able to give a guarantee demanded by Russia that NATO will not further expand.

He says the focus of the summit will be on whether the two countries will agree on a diplomatic framework to continue to exchange their views.

But he says that even if an agreement is reached, it would be difficult to implement and tensions won't ease immediately.

He also notes Putin could unilaterally recognize two breakaway regions in eastern Ukraine as nations, although such a possibility is not high.

He says that in this case, he cannot rule out the possibility that Russia could invade Ukraine before doing so.

Abiru says Russia's actions in the next week or two should be the focus of attention.