Donald Trump signed an order allowing Montenegro to join the North Atlantic Treaty Organization.

Though he previously said the organization was “obsolete,” the president said the inclusion of Montenegro in NATO would not “have the effect of increasing the overall percentage share of the United States in the common budgets of NATO” or “detract from the ability of the United States to meet or to fund its military requirements outside the North Atlantic area” in a letter to Vice President Mike Pence Tuesday.

Sean Spicer said the U.S. looks forward to further strengthening “our already strong relationship with Montenegro and looks forward to formally welcoming the country as the twenty-ninth member of the NATO Alliance.”

“President Trump looks forward to the May 25 NATO Leaders Meeting in Brussels and the opportunity to reaffirm those fundamental and enduring transatlantic values,” the press secretary said in a statement.

“Montenegro will be there as well, signaling to other NATO aspirants that the door to membership in the Euro-Atlantic community of nations remains open and that countries in the Western Balkans are free to choose their own future and select their own partners without outside interference or intimidation.”

[dcquiz] “The United States will work to further strengthen our already strong relationship with Montenegro and looks forward to formally welcoming the country as the twenty-ninth member of the NATO Alliance.”

In an op-ed published in Time Tuesday, Sen. Rand Paul said he inviting Montenegro to joint NATO was against U.S. interests.

“For decades, NATO has been an organization where the U.S. disproportionately spends our blood and treasure,” Paul wrote. “The other NATO countries have largely hitched a ride to the U.S. train that subsidizes their defenses and allows them to direct their revenues to domestic pursuits.”

“Adding a country with fewer than 2,000 soldiers to NATO is not in our self-interest. There is no national security interest that an alliance with Montenegro will advance. If we invite Montenegro into NATO, it will be a one-way street with the U.S. committing to defend yet another country.”

“The Senate hearing on admitting Montenegro to NATO was really just a Russia-bashing session. Not one word was said of how allowing Montenegro into NATO would advance our national security. Even the citizens of Montenegro are divided on entry into NATO.”

In an interview with a German newspaper in January, Trump described NATO as “obsolete.”

“It’s obsolete, first because it was designed many, many years ago,” he was quoted as saying. “Secondly, countries aren’t paying what they should.”

But he has come a long way from that comment in January, and he has repeatedly praised the organization since taking office.

“We strongly support NATO, an alliance forged through the bonds of two world wars that dethroned fascism, and a Cold War, and defeated communism,” he said during his first speech to Congress.