From good Chief WaPo, same kind of lead-in, also without informing detail, as the NYT headline:

President Biden landed Wednesday in Brussels, the first stop on a European trip meant to bolster the NATO alliance amid Russia’s invasion of Ukraine.

... This is Biden’s third overseas trip since taking office. 

Would the adjective "only" be appropriate there?

...
“For the past few months, the West has been united,” national security adviser Jake Sullivan said Tuesday. “The president is traveling to Europe to ensure that we stay united, to cement our collective resolve, to send a powerful message that we are prepared and committed to this for as long as it takes.”

What are the reasons he would have to "ensure"? Is he unsure?

...
Sullivan said Biden would speak Friday about the energy issues of Europe, which is more reliant on Russian oil and gas than the United States, before heading to Poland. The European Commission has presented a plan to dramatically cut Russian gas imports this year in response to the war.

Asked as he left the White House about his message to world leaders, Biden said he will “say it when I get there.” ...

Okay, that's fair, "I'll say it when I get there."