He added: "The U.N. investigation mission should be given an opportunity to succeed."
Nesirky said that Secretary-General Ban Ki-moon spoke with the head of the U.N. chemical weapons inspection team, Ake Sellstrom, earlier Sunday and asked him to accelerate the testing process, "and to report the results to him as soon as possible."
Nesirky also said that two Syrian government officials are observing the process as mandated by the guidelines that safeguard the samples' chain of custody. He declined to say whether they would be accompanying the samples, which the team collected at the site of the purported attack in the Damascus suburb of Ghouta, to the various laboratories.
They will be sent Monday to laboratories around Europe to check them for traces of poison gas.
Nesirky declined to say when the results might be in. "We are not giving a timeline," he said.
On Saturday, Ban met in New York with U.N. disarmament chief Angela Kane who had just returned from Damascus after days of tense negotiations with Syrian officials over the U.N. probe into the apparent poison gas attack.
The inspectors left Syria and flew out of Lebanon to the Netherlands early Saturday after carrying out four days of inspections.
Nesirky has said that under an agreement between Damascus and the United Nations the inspection team's mandate is limited to determining whether chemical weapons were used rather than trying to assign blame for the attack.