Group of Eight leaders said Wednesday that they deplored last month's post-election violence in Iran, adding that while they remained committed to seeking a diplomatic solution to Iran's contentious nuclear program, if no progress is made, leaders will reach new decisions at a G-20 economic summit in Pittsburgh in late September. In a series of declarations on global security threats, the G-8 also condemned "in the strongest terms" North Korea's nuclear tests and ballistic missile launches in defiance of UN resolutions. And they urged Afghanistan to ensure credible elections next month. French President Nicolas Sarkozy said the statement on Teheran by G-8 leaders "shows the unity of the G-8 against the situation in Iran." But the leaders stopped short of calling for new sanctions or tougher action. The US portrayed the statement as aggressive, even though the leaders took a weaker, compromise approach that specified no potential action against Iran for its post-election crackdown. Obama's undersecretary of state for political affairs, William Burns, said the agreed-upon language was "significant in that you have all eight members of the group indicating they have serious concern." "I think it's a strong statement and it reflects a real sense of urgency," Burns said. The G-8 leaders devoted a working dinner Wednesday to foreign policy issues, inviting to the table European Commission President Jose Manuel Barroso and Sweden's Prime Minister Fredrik Reinfeldt, whose country holds the EU rotating presidency. The leaders said they remained "seriously concerned" about Iran's crackdown of protests following a contentious election last month where incumbent President (Mahmoud) Ahmadinejad declared victory. The statement said G-8 leaders "deplore post-electoral violence, which led to the loss of lives of Iranian civilians." They also "condemn the declarations of President Ahmadinejad denying the Holocaust." G-8 leaders said they welcomed US President Barack Obama's willingness to engage in direct talks with Tehran. "We sincerely hope that Iran will seize this opportunity to give diplomacy a chance to find a negotiated solution to the nuclear issue," the statement said. Sarkozy said Iran needs to respond to the overtures made by the international community and said leaders will make new decisions at a G-20 economic summit in the US city of Pittsburgh late September if no progress has been made. Italy has repeatedly said the offer for dialogue was not indefinite. The statement also criticizes restrictions on the media and signaled support to Britain, whose embassy staff in Tehran was detained. Nine staffers, all Iranian nationals, were held and all but one have been freed. The statement said: "Embassies in Iran must be permitted to exercise their functions effectively and that any arbitrary restrictions or intimidation in this regard were totally unacceptable." Sarkozy called the violence on protesters "shocking" and called for the release of a young French teacher who was arrested this month at the Tehran airport and accused of espionage. France has said it would like stronger sanctions in response to the crackdown after a disputed presidential election last month. But Russia has rejected the idea and it has been unclear if countries like Germany and Italy, which have significant economic ties to Iran, would be willing to back them. Any sanctions would be imposed by the UN Security Council, but an agreement within the G-8, which includes four permanent members of the Security Council, would give the United Nations strong impetus to act. "For there to be sanctions you need unanimity. We made a step immense toward this unanimity," Sarkozy said. He said Russian President Dmitry Medvedev was "constructive."