U.S. national security adviser John Bolton met with Russian President Vladimir Putin in Moscow on Wednesday to discuss a potential meeting between President Trump and Putin. The meeting will likely take place in mid-July, and the details are expected to be announced on Thursday. While it might not seem that important when exactly these two leaders meet, the timing of the meeting matters for NATO allies.

After Trump’s last-minute Twitter announcement reversing U.S. support for the G-7 statement earlier this month and his high-profile meeting with North Korea’s Kim Jong Un, U.S. allies are weary of foreign policy surprises from the White House. The announcement of Trump’s meeting with Putin has likely spurred a new wave of speculation about what the president might agree to with the Russian leader and what the implications for NATO might be.

U.S. allies would like to have Trump’s ear first on his scheduled trip to Europe for the NATO summit on July 11 and 12 in Brussels. After the summit, Trump will travel to Britain on July 13.

While the summit may prove contentious after the drama of the G-7 meeting in Canada and Trump’s push for NATO members to meet defense spending commitments at the summit last year, it would be a chance for leaders to share concerns before Trump meets with Putin.

Their concern is that if Trump speaks to Putin first, he might agree to something with the Kremlin before NATO allies have a chance to engage with him. The other concern, drawn from Trump’s early departure from the G-7 summit to head to Singapore to meet with Kim Jong Un, is that a back-to-back meeting schedule could overshadow the goals of the NATO summit. To offset both of these issues, Trump should first meet with longtime U.S. allies and reaffirm his commitment to NATO before sitting down with Putin.

Although U.S.-Russia relations are undoubtedly important and the first dedicated meeting between Trump and Putin offers a great opportunity for President Trump, that meeting should not come at the cost of overshadowing commitments to longstanding allies.