Secretary of State Marco Rubio speaks during a signing ceremony with Parguayan Foreign Minister Rubén Ramírez Lezcano at the State Department in Washington, DC, on Thursday.

President Donald Trump hopes to reach “some stoppage in fighting” between Russia and Ukraine to create space for negotiations on a full end to the war, according to Secretary of State Marco Rubio.

Speaking ahead of Friday’s summit between Trump and Russian President Vladimir Putin, Rubio said the US is “hopeful” that progress can be made and stressed the importance of a ceasefire.

“The longer these wars go on, the harder they are to end,” Rubio said, adding that prolonging fighting impacts which side has “leverage” in negotiations. “That’s the reality of ongoing fighting, which is why a ceasefire is so critical,” he added.

The top US diplomat noted that “to achieve a peace, I think we all recognize there will have to be some conversation about security guarantees, there’ll have to be some conversation about territorial disputes and claims and what they’re fighting over.”

“To have a peace agreement between Ukraine and Russia, you will need agreement from both Ukraine and Russia,” he said.

Rubio reiterated the view of Trump that the US will likely know “very early” in the meeting “whether something is possible or not.”

Trump himself has said that he believes he will be able to gauge the potential for progress within minutes of meeting his Russian counterpart.

Rubio said for the summit, preparations are “going very fast because this was put together very quickly.”

“We’ll see how tomorrow plays out,” he said.