Iran warned Monday that, while some progress had been made, it was not yet close to striking a deal with the United States to end the Middle East war, after a weekend of mixed messages from Washington and Tehran.World oil prices tumbled on renewed optimism about an agreement, after top US diplomat Marco Rubio suggested a deal could be reached within the day -- but Iran's foreign ministry spokesman responded: "No one can make such a claim."

Oil prices saw a rise on Friday amid doubts about U.S.-Iran peace talks. Investors are concerned about Middle East instability and potential supply disruptions. Despite some…

The conflicting statements on key issues left it unclear if the two sides were any closer to a deal after renewed threats of escalation in recent days