Russian media are reporting that six Western countries and Iran have made little progress on the first day of their negotiations over Tehran’s nuclear program in Moscow on Monday. Sources familiar with the discussions say that the first-day talks were intense and frank, though no tangible results or breakthroughs were produced.

Michael Mann, spokesman for the EU High Representative for Foreign Affairs and Security Policy, said the negotiations were tough but more substantial than those of a previous meeting in Baghdad. He added that the two sides will resume talks on Tuesday.

A high-ranking Iranian delegate also said that the first-day talks were constructive and cautious, with two sides finding common ground on some issues.

In the initial stage, the atmosphere of the negotiations was reported to be negative and near breakdown. But the two sides still agreed to resume discussions on Tuesday.