Iran's parliament approved a controversial bill Tuesday that it said would protect the country's nuclear program, but which could also hinder final negotiations on a deal with world powers.

The move re-exposed persistent tension between President Hassan Rouhani's government and lawmakers in Tehran, where hardliners routinely voice doubt about the merit of talking to the West.

Britain and France insisted Monday that any deal on Iran's contested nuclear program must include a comprehensive verification regime to ensure Tehran sticks to its commitments, as the clock ticks down to an end-of-month deadline.

After years of tortuous negotiations, both sides are racing to agree a deal by June 30 that would see Iran open up its nuclear program to allay concerns it is seeking atomic weapons, in return for the West lifting punishing economic sanctions.

Francois Hollande and German Chancellor Angela Merkel lamented the "insufficient" progress in resolving the Ukraine crisis after a telephone conversation Monday with Russian President Vladimir Putin, according to a source close to the French president.

"The chancellor and the president (Hollande) raised the need to put pressure on the various parties" given that progress is "insufficient," the source said, a day before foreign ministers from Ukraine, Russia, France and Germany hold talks in Paris on the crisis.

German authorities Monday released Al-Jazeera journalist Ahmed Mansour, two days after detaining him at the request of his native Egypt in a move that sparked outrage from rights groups.

"I'm free, I'm free, I'm free," Mansour exclaimed outside the Berlin prison, greeted by dozens of cheering supporters. "Thanks to people around the world who supported me in the last days!"

U.S. Secretary of Defense Ashton Carter on a visit to Berlin Monday touted Washington's bid to station heavy military equipment in eastern Europe as an "important" move to help counter any Russian threat.

Amid mounting fears about Russia's actions and intentions in the former Soviet bloc, Washington has announced it is poised to move heavy equipment to the region to support training efforts, prompting Moscow to hit back with a threat to boost its own nuclear arsenal.

EU foreign ministers formally agreed Monday to prolong to January 2016 damaging economic sanctions against Russia to ensure it fully implements Ukraine peace accords, officials said.

"EU has extended economic sanctions against Russia until 31 January 2016, with a view to complete implementation of (the) Minsk agreement," an EU spokeswoman said in a tweeted message.

Around 5,000 people joined a Berlin demonstration on Sunday by a controversial protest group which dug mock graves in front of parliament to highlight Europe's deadly migration crisis, police said.

The political art group calling itself "Center for Political Beauty" had planned to march to Chancellor Angela Merkel's offices with what it said were the corpses of dead migrants and bury them outside.

A prominent Al-Jazeera journalist was being held in German police custody Sunday pending a court decision on his further detention on an arrest warrant issued by his native Egypt.

In a case that prompted angry questions about press freedom and German relations with Egypt under President Abdel Fattah al-Sisi, television journalist Ahmed Mansour was arrested Saturday at a Berlin airport having been accused by Cairo of committing "several crimes."

German Foreign Minister Frank-Walter Steinmeier said Wednesday that EU member states remain "far from consensus" on how to distribute refugees between them.

"These are difficult discussions we're having at the moment, and all my conversations with European colleagues show that we remain far from consensus and that a lot persuasion will still be necessary," he said.

Nuclear armed states continue to upgrade their stockpiles despite an international trend towards disarmament, the Stockholm International Peace Research Institute reported Monday. 

Between 2010 and 2015 the number of warheads fell from 22,600 to 15,850 according to the institute's annual disarmament report which said the U.S. and Russia represented the bulk of the reduction.