The United States on Thursday accused Iran of sponsoring "terrorism" at a level unseen in decades and said that the separate threat from Al-Qaeda has been significantly degraded.
Syrian President Bashar al-Assad threatened Israel with renewed fighting in the Golan Heights and said Russia was committed to supplying him with advanced missiles.
Embattled Syrian President Bashar al-Assad, who is facing a two-year rebellion against his rule, will run for a third term in 2014 if the people want him to.
The United States demanded the immediate withdrawal of Hezbollah fighters from Syria on Wednesday, saying their active role in combat there was an "extremely dangerous escalation."
Failure to agree on who will take part in an international conference on the Syria could thwart hopes that the make-or-break meeting will be held in June.
The United States said Tuesday it supports the European Union's decision to ease an arms embargo on Syria as a means of showing support for rebels despite America's own refusal to provide weapons.
French authorities will analyse samples brought back from Syria by two journalists after they reported the Syrian army was using chemical weapons against rebel forces.
International efforts to end the unrest in Syria accelerate Monday with key talks in Paris and Brussels, amid a push for a new peace conference despite growing divisions within the Syrian opposition.
Syria's main opposition group gathers Thursday for a landmark conference in Istanbul, Turkey, to discuss peace talks with the regime, as rebels on the ground suffer a massive army onslaught.
Shots fired from Syria hit the central Israeli-occupied Golan Heights overnight, a military spokeswoman said Monday morning, causing no harm or damage.
Aid organisation Oxfam warned on Monday that the warmer weather will increase health-related risks for hundreds of thousands of Syrian refugees in Jordan and Lebanon, and appealed for urgent funds.
US President Barack Obama and Turkish Prime Minister Recep Tayyip Erdogan insisted Thursday Bashar al-Assad must step down amid a flurry of moves to organize peace talks to end Syria's bloody civil war.
French President Francois Hollande said Thursday that more efforts were needed to convince Moscow to drop its support for Syrian leader Bashar al-Assad.
The UN General Assembly condemned President Bashar al-Assad's "escalation" of the Syrian war on Wednesday as rebels battled to free inmates from a prison in the key city of Aleppo.
Turkey said Sunday it had arrested nine people over bombings that killed 46 in a town near the Syrian border and warned Damascus a red line had been crossed.