The top British and French diplomats say more work needs to be done before world powers can reach a deal in nuclear talks with Iran.
As negotiations in Geneva went into a third day Saturday, British Foreign Secretary William Hague said negotiations have made "very good progress," but there are "still important issues to resolve." Hague said it is too early to tell if a "successful conclusion" can be reached Saturday.
Earlier in the day, French Foreign Minister Laurent Fabius told France Inter radio there are major stumbling blocks in an initial proposed text on a deal.
The French envoy's remarks echoed those of U.S. Secretary of State John Kerry, who said after Friday's session that "some important gaps" remain in the talks, but that the parties are "working hard."
Diplomats said the talks among Kerry, his Iranian counterpart Mohammad Javad Zarif and key European officials made progress but that there is still a lot of work to do.
Russian Foreign Minister Sergei Lavrov joins the talks Saturday, and China is sending a top official in an effort to secure a deal over Iran's disputed nuclear program.
U.S. President Barack Obama on Friday called Israeli Prime Minister Benjamin Netanyahu, who has been opposed to a potential nuclear deal with Iran. White House officials said President Obama updated Mr. Netanyahu on the ongoing talks and reaffirmed his commitment to preventing Iran from obtaining a nuclear weapon.
Earlier Friday, Mr. Netanyahu told reporters ahead of a meeting with Kerry in Tel Aviv that Iran "got everything and paid nothing" because it is not reducing in any way its nuclear enrichment capability.
"Iran got the deal of the century and the international community got a bad deal. This is a very bad deal and Israel utterly rejects it."
Major world powers are concerned that Iran is trying to develop nuclear weapons. Iran says its nuclear program is for peaceful purposes.
Speaking Friday, Kerry said diplomats are working to see if they can "narrow some differences" with Iran over the issue.
"I don't think anybody should mistake that there are some important gaps that have to be closed."
Progress was reported this week in efforts to convince Iran to scale back its nuclear program in exchange for sanctions relief.
In Washington, President Barack Obama said the deal being discussed would offer "modest relief" from the sanctions, but that most would stay in place.
"We can provide them some very modest relief, but keeping the sanctions architecture in place, keeping the core sanctions in place, so that if it turned out during the course of the six months when we're trying to resolve some these bigger issues that they're backing out of deal or they're not following through on it, or they're not willing to go forward and finish the job of giving us assurances that they're not developing a nuclear weapon, we can crank that dial back up."
It is not clear what Iran is willing to concede. Foreign Minister Zarif said Tehran is not willing to suspend its uranium enrichment program entirely, but would consider scaling it back.
This is the second meeting of the so-called P5+1 countries since Iranian President Hasan Rouhani took power in August, on promises of reaching a nuclear deal with the West.