Ryan, the nation’s highest-ranking Republican, isn’t promising to help his party’s presumptive presidential nominee on the campaign trail. He’s not publicly backing any of Trump’s policies. And even as he vows to vote for the brash billionaire, Ryan is reminding voters he doesn’t support Trump’s confrontational style.

“It is my hope the campaign improves its tone as we go forward and it’s all a campaign we can be proud of,” Ryan told The Associated Press.

The Wisconsin Republican’s endorsement may have ended a weekslong holdout that exposed deep divisions within the GOP. But his comments during an exclusive interview with the AP exposed lingering reservations, suggesting that Ryan’s shift was driven more by a deep desire to defeat leading Democrat Hillary Clinton than to support Trump.

“It’s very clear to me that Hillary is in no certain way going to be advancing our principles and policies. She’s promising another Obama term,” Ryan said Thursday. “It’s also become clear to me through my conversations that Donald Trump is somebody I know is comfortable with these principles and general policies.”

Ryan couched his endorsement around what he called an increased comfort level with Trump’s approach toward Ryan’s policy priorities, including halting overreach of the president and executive branch. Yet he offered no public support for Trump’s policy priorities in the AP interview. He also insisted he made no “deals” with the New York businessman in exchange for his endorsement.

“I had friends wishing I wouldn’t support him. I had friends wishing I would,” Ryan said from his congressional office just down the hill from where he lives in the small Wisconsin city where he grew up. “I really didn’t feel any pressure, other than my goal is to make sure that we’re unified so that we’re at full strength in the fall so we can win the election.”

Ryan’s announcement marked a significant step for a GOP desperately trying to come together ahead of a general election matchup against Clinton, the likely Democratic nominee.

Some GOP leaders have vowed not to support Trump, including 2012 Republican presidential nominee Mitt Romney, who tapped Ryan as his running mate. Just a day earlier, Romney signaled support for a possible third-party candidate instead of the presumptive Republican nominee.

As the GOP’s “Never Trump” movement struggled to identify a viable alternative, many believed it was only a matter of time before Ryan fell in line. The endorsement, he said, was not the product of any deal with the billionaire developer, but a decision based on “an understanding of our mutually agreed upon principles.”

Ryan said he specifically wanted to go over Trump’s approach to executive power and judicial appointments, and his position on abortion.

“Those conversations took some time,” he said and added: “I feel much more comfortable that he’s in the same page with us. Most importantly, it is obvious that Hillary Clinton is not.”

Ryan’s announcement came as Clinton delivered a foreign policy speech excoriating Trump’s approach. Electing Trump, she said, would be “a historic mistake.”

Ryan first outlined his support for the New York billionaire in a column published in his hometown newspaper. He had shocked the political world last month by refusing to endorse Trump once the real estate mogul became the last major Republican presidential contender still in the race.

The pair spoke privately in a series of Washington meetings last month and their campaigns have maintained contact. Ryan said he made the decision to formally endorse Trump earlier in the week.

Major differences remain, however. And conservative leaders across the country continue to have deep reservations about Trump’s devotion to Republican principles and his temperament.

In particular, Ryan has embraced major changes to Medicare and Social Security as his signature issue on Capitol Hill. Most Republicans in Congress have followed Ryan’s plan to reduce the cost of the popular programs, which are contributing to the national debt.

In contrast, Trump has repeatedly promised not to touch Medicare and Social Security, echoing a position more commonly adopted by Democrats.

The two also break on immigration. Trump wants to deport more than 11 million immigrants in the country illegally in addition to imposing a temporary ban on Muslims from entering the U.S. Ryan opposes both policies.

“We obviously have a different kind of style and tone. That’s very clear,” Ryan told the AP. “Anyone who knows anything about us knows that. But what really, ultimately matters is how best can we make sure these principles and policies get enacted in 2017. And it is clear that is far more likely to happen under a Trump presidency than a Clinton presidency.”