A "peace convoy" was stalled at the Mexican border by trade restrictions, but organizers say the 41 vehicles carrying food and medical supplies for Nicaragua won't budge until they are allowed to cross the Rio Grande.

"Right now, we're prepared to stay here until we are allowed to leave our own country," said Gerry Condon, one of the nearly 100 participants in the Veterans Peace Convoy to Nicaragua."We feel like we are being held hostage with this humanitarian aid."

The group held a closed meeting Wednesday night at its Laredo campground base to plan actions "that would be dramatic, that would up the ante," said Condon, a Vietnam veteran from Santa Cruz, Calif.

They marched Wednesday through Nuevo Laredo, Mexico, just across the river, carrying signs and chanting slogans, then briefly blocked one of the international bridges with Mexican supporters.

New York lawyer Stephen Somerstein, traveling with the convoy, said attorneys with the New York-based Center for Constitutional Rights are representing the convoy in its negotiations with the Treasury Department.

Somerstein said he expected demonstrations of support around the country, including a protest planned today at the federal building in San Francisco.

Convoy organizers, who oppose the U.S government's trade restrictions against Nicaragua and aid to the Contras who have fought to overthrow the leftist government, had planned to cross the Mexican border Wednesday morning.

They had hoped to reach Nicaragua on June 18.

But on Tuesday night, federal officials advised them that although the food, clothing and medical supplies would be allowed to be taken to Nicaragua, the vehicles they planned to leave in the Central American nation for distribution of the aid would violate a trade embargo.

The Nicaraguan Trade Control Regulations of the Treasury Department's Office of Foreign Assets Control prohibit the unlicensed export of goods to Nicaragua, except for "donated articles such as food, clothing and medicine, intended to be used to relieve human suffering."