After Venezuelan President Hugo Chavez was temporarily deposed last Friday in a failed coup, the Bush administration tried in vain to persuade a leader of the anti-Chavez coalition not to dissolve the National Assembly.

The administration felt it was important for the assembly to remain intact because it is the only body authorized to appoint a new president in the event the office is vacated, U.S. officials said Wednesday.

But interim leader Pedro Carmona ignored the appeal of Ambassador Charles Shapiro, delivered at mid-afternoon Friday, and dissolved the assembly and had himself sworn in as Chavez's replacement, a senior U.S. official said, speaking on condition of anonymity.

Shapiro said Wednesday that he also met with Carmona on Saturday to ensure the security of some 25,000 U.S. citizens living in Venezuela.

The U.S. ambassador said he urged Carmona to restore the National Assembly, or congress, which Carmona had dismissed with a decree that was widely seen as unconstitutional. He said he also urged Carmona to welcome a mission from the Organization of American States.

Shapiro defended U.S. policy toward the foiled coup.

"Yes, there was an alteration of constitutional order, and we condemned that along with the other countries in a special session of the Permanent Council of the OAS," Shapiro told reporters during a meeting in Caracas of the Venezuelan-American Chamber of Commerce.

"We have been very consistent in our policy of opposing any attempt to change the government outside of the constitutional framework," he said.

The ambassador denied that any U.S. Embassy officials were involved in any activities related to the failed coup.

"I gave instructions to say no to any suggestion to contacts, friends, whoever, about any change outside constitutional order," he said.

"We had contact with people from the opposition as well as with the people of President Chavez throughout that period," Shapiro said.

Carmona's decision to ignore constitutional succession procedures is believed to be one of several reasons why his coalition was driven from office so quickly. Helped along by mass demonstrations by his supporters, Chavez was reinstated on Sunday.

"The message to new presidents should be to focus on democracy. That is exactly what the United States has done in Venezuela and exactly what we have done for more than 20 years throughout our hemisphere," White House spokesman Ari Fleischer said in defending the U.S. contact.

The senior official who confirmed the Shapiro-Carmona phone call said the administration felt deceived by Venezuelan military officials who claimed that Chavez had signed a resignation letter early on Friday.

He said that when U.S. officials asked for proof, a resignation letter was sent to the State Department by fax — without Chavez's signature.

Nonetheless, the State Department took the military claim of a resignation at face value, asserting in an official statement at noon on Friday that Chavez had indeed resigned.

When the State Department learned early Friday that Chavez was in military custody, U.S. diplomats, worried that he would become a martyr, strongly urged that he not be harmed.

Chavez said later he had not been mistreated.

According to the official, Chavez's opponents were told repeatedly the United States would not support a coup against the president. If they wanted a new president, they were told, the constitution provided three legal options, including provisions for a referendum.

At no time did the United States suggest that these options be exercised, the official said, adding that any such action was up to Venezuelans.

Meanwhile Wednesday, foreign ministers of the OAS were convening in Washington for a special meeting on Thursday to discuss the Venezuelan situation.

Officials said it was not clear whether Secretary of State Colin Powell would attend the meeting. Powell was returning before dawn Thursday from his long trip to the Middle East.

The ministers will hear a report from OAS Secretary General Cesar Gaviria, who has been on a fact-finding mission in Venezuela since Monday.

"Polarization has to give way to reconciliation and understanding," Gaviria said after meeting Chavez on Tuesday.

The OAS permanent council met late Saturday and approved, with United States support, a resolution condemning the "alteration of constitutional order" in Venezuela.