WASHINGTON — President Joe Biden said Thursday that the United States fully supports Sweden and Finland’s bids to join NATO after both nations began the formal process of applying to the alliance.

Biden, flanked by Finnish President Sauli Niinisto and Swedish Prime Minister Magdalena Andersson, said the two countries would “make NATO stronger.” He called their moves to join the pact a “victory for democracy.”

The president pledged to work with Congress — which has to ratify U.S. approval of NATO bids — and the other 29 members of the world’s most powerful military alliance to swiftly bring Sweden and Finland into the group. 

“There is no question, NATO is relevant, it is effective and it is needed now more than ever,” Biden said following a trilateral meeting in Washington with the leaders.

The push comes as Russia’s assault on Ukraine has raised fears for other countries in the region. Moscow, long wary of NATO expansion, has opposed the two nations’ plans to join the alliance.

Earlier in the week, Russian President Vladimir Putin said Finland and Sweden’s entry into NATO and any “expansion of military infrastructure into this territory will certainly cause our response.”

Similarly, the Russian Foreign Ministry said in a statement Monday that Russia “will be forced to take retaliatory steps, both of a military-technical and other nature, in order to stop the threats to its national security arising in this regard.”

Both Finland and Sweden already meet many of the requirements to be NATO members. Those include having a functioning democratic political system, a willingness to provide economic transparency and the ability to make military contributions to NATO missions.

However, all 30 NATO members must approve a country’s bid for it to be accepted into the alliance.

Earlier in the week, Turkish President Recep Tayyip Erdogan said he would not approve the NATO applications of both Sweden and Finland. He has cited their support for Kurdish organizations that Turkey considers security threats.

Erdogan added that delegations from the nations should not bother coming to Turkey to try to convince him otherwise.

Niinisto and Andersson both addressed Erdogan’s concerns during remarks in the White House Rose Garden.

“We take terrorism seriously, and we condemn terrorism in all its forms,” Niinisto said, adding that Finland routinely works with allies to combat terror plots.

Andersson said Sweden was speaking with all NATO member countries and holding additional talks with Turkey to discuss specific concerns.