Finland's entry into NATO will be "smooth and swift" once the country applies, NATO General Secretary Jens Stoltenberg said Thursday.

Stoltenberg made the statement hours after Finish President Sauli Niinistö and Prime Minister Sanna Marin issued a joint statement calling for Finland to apply for NATO membership "without delay."

"Should Finland decide to apply, they would be warmly welcomed into NATO, and the accession process would be smooth and swift," Stoltenberg said Thursday.

UK SHORES UP DEFENSIVE ALLIANCE WITH SWEDEN, FINLAND AS COUNTRIES FLOAT NATO MEMBERSHIP

NATO Secretary General Jens Stoltenberg addresses the media during a joint statement with German Chancellor Olaf Scholz prior to a meeting at the Chancellery in Berlin, Germany, Thursday, March 17, 2022. 

NATO Secretary General Jens Stoltenberg addresses the media during a joint statement with German Chancellor Olaf Scholz prior to a meeting at the Chancellery in Berlin, Germany, Thursday, March 17, 2022.  (AP Photo/Michael Sohn, Pool)

Findland's membership in NATO would come as a direct result of Russian President Vladimir Putin's invasion of Ukraine. Moscow released a statement attempting to ward off Finland's membership on Thursday.

"Finland’s entry into NATO will become a threat to Russia," Putin press secretary Dmitry Peskov said. "The next expansion of NATO does not make our continent more stable and secure."

"Of course, all this will become elements for a special analysis and development of the necessary measures in order to balance the situation and ensure our security," he added.

CLICK HERE TO GET THE FOX NEWS APP 

Finland's entry into NATO would be particularly consequential given its shared border with Russia. None of Russia's direct neighbors are currently members of the alliance, and Ukraine's ambitions for joining NATO were a central reason Putin had for invading the country.

The Kremlin warned last month that it would deploy nuclear and hypersonic missiles to the region if Finland and Sweden join NATO.