Iran and the US are due to hold a second round of talks in Oman on Saturday over Tehran's escalating nuclear program, with President Donald Trump threatening military action if there is no deal.
"It is imperative for the world that we create a tough, fair deal that will endure, and that is what President Trump has asked me to do," Witkoff stated.
Khamenei said Tehran retains a "very pessimistic" overall view of the US and should not tie its national affairs to nuclear negotiations.
Lavrov praised Trump's "common sense" and for saying that previous US support of Ukraine's bid to join the NATO military alliance was a major cause of the war in Ukraine.
Steve Witkoff, Trump’s envoy and the US representative in nuclear talks with Iran’s foreign minister, to Fox: "Iran must not possess nuclear weapons, and it should not enrich uranium beyond 3.67%."
Keith Kellogg proposed a partition of Ukraine resembling post-WWII Berlin, with the UK and France controlling the western zone, Russia in the east, and a demilitarized buffer zone in between.
US-Iran talks were focused on sanctions against the Islamic Republic and wars in the Middle East, according to an Omani source.
This comes after Trump expressed his frustration with Vladimir Putin's response to his administration's efforts to secure a ceasefire deal between Kyiv and Moscow.
A weekly selection of opinions and analyses from the Arab media around the world.
US envoy Witkoff proposed giving Russia control over Ukrainian regions for a ceasefire, but this was rejected by Kyiv and US officials. His influence has raised concerns about unclear US policy.