Finland's expected application to join NATO will be discussed at the alliance's headquarters in Brussels and will receive a warm welcome, NATO Secretary General Jens Stoltenberg said.

"The decision to join is entirely in Finland's hands. A warm welcome awaits Finland when it applies. The message from the 30 allies is that Finland is warmly welcomed, with open arms. We will ensure that the process is quick and efficient," Stoltenberg said Thursday on Finnish broadcaster Yle.

He said Finland could be supported, for example, by political declarations, statements or NATO exercises in its neighboring region.

"There are many ways in which we can express that Finland's security is important to NATO allies," Stoltenberg stressed.

Finland's membership would strengthen NATO, he said. It has a modern and well-equipped defense force, is investing in new fighter jets and democratic structures, he said.

"All of this will affect Finland's contribution to transatlantic security," Stoltenberg said.