Mr McCully's statement today said the Russian suggestions deserved constructive consideration.
"The international community needs to take appropriate steps to ensure that there can be no further use of chemical weapons in Syria."
Mr Key spoke to reporters in Auckland today about last night's advice while offering moderate encouragement for the Russian-led initiative to get Syria to surrender its chemical weapons.
Russia's President Vladimir Putin has since put conditions around the initiative, saying that the United States would have to first withdraw any threat of a military strike on Syria.
Mr Key said the proposition was worth looking at "but it would have to be done quickly, it would have to be complete and it would have to be the end of chemical weapons in Syria".
Mr Key also defended threats by United States President Barack Obama to punish Syria and said what had happened there - a postponement of the congressional vote which looked like failing - was not a back-down.
"As the superpower of the world," Mr Key said "America has a responsibility actually to try and defend people who can't defend themselves through no fault of their own."
He believed the dialogue in the lead-up to the latest proposition had put pressure on Syria via Russia to make the offer.
"If in the end as a result of the comment President Obama has been making...we were to see chemical weapons eradicated in Syria, then you've got to say that's a win for President Obama and the world and particularly for the people of Syria."
Mr McCully is expected to lead a briefing of other political parties on Friday with MFAT officials.
Labour foreign affairs spokesman Phil Goff said the Security Council should work together to achieve a UN supervised collection and destruction of chemical weapons in Syria.
It made much more sense than a military strike.
"A strike could kill further thousands of civilians through the release of poisonous gas."
A military strike could also result in the loss of control over the stockpiles of chemical weapons and increase the risk of their use.
Mr Goff said the Security Council should also insist that all countries cease supplying weapons to warring parties in Syria which was fuelling the conflict.