Tokyo, May 22 -- Oil prices climbed on Friday as uncertainty around peace negotiations continued to cloud the market, even as reports suggested that differences between the two sides have narrowed.

The sticking points over the uranium stockpile and control of the critical Strait of Hormuz continue to pose challenges to a breakthrough.

Secretary of State Marco Rubio said there have been "good signs" that have emerged from the talks, but he categorically said that a toll system in the Strait of Hormuz is unacceptable.

US President Donald Trump said that the uranium stockpile will eventually be recovered, while Iran continued to maintain that it is meant for peaceful purposes.

"We will get it. We don't need it, we don't want it. We'll pr...