"New Zealand's contribution to the OPCW Trust Fund for Syria will now assist in implementing the agreement."
Mr McCully said the humanitarian funding would go to the Red Cross to help those affected by the conflict within Syria.
It would also go to the World Food Programme to help Syrian refugees in Jordan, and a UN programme to help Palestinian refugees affected by the conflict.
The extra funding brings New Zealand's contributions to humanitarian relief efforts for those affected by the conflict in Syria to $7.46m.
Mr Key today said the Government would not rule out further funding if required, but it was unlikely New Zealand would send personnel to assist with dealing with the chemical weapons.
Meanwhile, New Zealand has announced it would open a new High Commission in Barbados to increase its diplomatic presence in the Caribbean.
Mr Key made the announcement after a meeting with foreign ministers of the 15 member Caribbean Community at the UN General Assembly in New York today.
"Like our Pacific region, the Caribbean is made up of a group of small island states and having our voice heard on the key global issues is important for us and for the relevance of the Security Council," he said.
Mr Key recently attended the Pacific Islands Forum in the Marshall Islands and said it was useful to see how its Caribbean counterpart operated.
"New Zealand understands the importance of a regional approach to overcoming the challenges small states can face on their own." he said.
"The similarity of issues and challenges faced by both regions - renewable energy, non-communicable diseases, oceans and fisheries management and disaster risk management - means we have much to learn from each other."
He said the announcement built on increased engagement with the region, including visits by Mr McCully and special envoy Sir Don McKinnon earlier this year.
Mr Key also announced an extension of New Zealand's Honorary Consul network in the Caribbean region.