Finland’s President Sauli Niinistö spoke with Russian President Vladimir Putin over the phone about the country’s plans to join NATO, Interfax news agency cited Bloomberg as saying on Saturday.

His office also confirmed the talk on Helsinki’s NATO membership plans, which is expected to be announced this week.

“The conversation was direct and straight-forward and it was conducted without aggravations. Avoiding tensions was considered important,” Niinistö was quoted as saying in a statement by his office. “The phone call was initiated by Finland.”

Russia has said Finnish entry to NATO poses a threat to which it will respond but has not specified how.