President Trump remains optimistic about his relationship with Russian leader Vladimir Putin, the White House said Monday, despite growing concerns about Russia’s alliance with Syria in the wake of lasts weekend’s chemical weapons attack in Damascus.

“The president still feels that if we can have a good relationship with Russia at some point, that’s a good thing for the world,” White House press secretary Sarah Sanders told reporters. “But at the same time, this president is going to be tough on Russia until we see some changes in behavior.”