WASHINGTON (AP) — President Barack Obama continues to ponder a final decision on whether to order a punitive strike on Syria over an alleged chemical weapons attack by the regime on rebel forces outside Damascus.

The administration says it has "high confidence" that some sort of nerve agent was used, killing 1,429 people.

Meanwhile, U.N. experts investigating the alleged chemical strike outside Damascus left Syria today, carrying with them blood urine and soil samples to be tested in laboratories in Europe.

Obama says any strike on Syria will be limited in scope and not include "boots on the ground." His only public interenational support comes from France and members of Congress have expressed various concerns.

Any U.S. action carries the potential to trigger retaliation by the Syrian regime or its proxies against U.S. allies in the region, such as Jordan, Turkey and Israel.