U.S. President Donald Trump and Russian President Vladimir Putin met face-to-face for the first time in six years, but came short of an agreement on a ceasefire in the Russia-Ukraine war.

At a joint press conference on Friday, following a three-hour meeting in Alaska, Trump deemed the talks were "very productive," but that they have yet to resolve some key issues.

Trump said although they made some headway, "there is no deal until there is a deal."

Putin, for his part, reiterated that all the root causes of the crisis must be eliminated. He added that he expected Ukraine and its European allies to accept the results of the latest negotiation, urging them not to "torpedo" the progress toward a resolution. 

While the two leaders expressed a will to continue their negotiation, a three-way meeting involving Ukrainian President Volodymyr Zelenskyy, which was anticipated upon a deal, is unlikely for the time being.

The three-and-a-half-year-old war will likely remain in a state of deadlock amid a delay in the announcement of a ceasefire.