Talks between Iran and six world powers -- U.S., U.K., China, France, Russia and Germany -- to finalize a draft nuclear agreement entered the final day on Tuesday. Iranian Foreign Minister Javad Zarif met with representatives from the P5+1 bloc of nations in the Swiss city of Lausanne in a last-ditch effort to achieve a breakthrough in the stalled negotiations.

The sides have until midnight to frame a draft agreement, and even as the deadline looms, chances of a breakthrough seem remote. Frank-Walter Steinmeier, the German foreign minister, reportedly said on Tuesday morning that the talks are in “a bit of a crisis.”

“Perhaps we will try a bit of a new approach. We will see,” Steinmeier reportedly said, echoing similar comments made by U.S. Secretary of State John Kerry on Monday, when he said that several “tricky issues” still remain to be resolved.

On the other hand, Russian Foreign Minister Sergei Lavrov, who is planning to return to Lausanne on Tuesday afternoon after departing for Moscow on Monday, reportedly said that there are “good prospects” of finalizing an agreement by the end of the day.

“The chances are high. They are probably not 100 percent but you can never be 100 percent certain of anything. The odds are quite ‘doable’ if none of the parties raise the stakes at the last minute,” Lavrov reportedly said.

The talks over Iran’s nuclear program have already been extended twice since November 2013. Although Iran has since agreed to a reduction in the number of active centrifuges in its nuclear plants in exchange for sanctions relief, the sides have failed to agree on the number of centrifuges Iran should be allowed to keep.