The move on Sunday means that members will have to strike their own bilateral free trade deals with Washington, the Kuwaiti foreign minister said.
"The GCC states have excluded the US from the collective agreements," Shaikh Muhammad al-Sabah said after attending a seminar on future talks with Washington for a Free Trade Agreement (FTA).
"We in the GCC will hold collective (trade) agreements with all countries except the United States," he added. The GCC groups Bahrain, Kuwait, Oman, Qatar, the United Arab Emirates and Saudi Arabia.
The US has signed an FTA with Bahrain, is negotiating for similar agreements with UAE and Oman, and plans to begin talks with Qatar and Kuwait in the near future.
Recently, GCC Secretary-General Abd al-Rahman al-Attiya said "the issue of free trade [agreements] with the United States ... is no longer a bone of contention between the GCC states".
He added that the issue was resolved "more than two weeks ago" during a meeting of the GCC finance and economy ministers held in Bahrain in the first week of May.
Saudi Arabia initially strongly opposed bilateral deals, arguing that bilateral free trade deals derail GCC economic integration plans. But it appears to have softened its position following a visit by Crown Prince Abd Allah bin Abd al-Aziz to Washington in April.
GCC states launched their unified customs union on 1 January 2003 and the oil-rich region was due to become a single customs zone by the end of 2005.
The council had also planned to establish a monetary union by the end of this year, a common market by 2007 and a single currency by the beginning of 2007.