CARACAS (Dow Jones)--A U.S. official Monday warned the government of Venezuela that it faces "consequences" for formally rejecting the White House's choice for envoy to Caracas.

U.S. State Department spokesman Philip J. Crowley told reporters in Washington it appears unlikely that ambassador-designate Larry Palmer, who still has to be confirmed by the U.S. Senate, will take up duties in Caracas as a result of the objection letter received earlier Monday from the government of President Hugo Chavez.

Crowley added since Venezuela has taken this action, "there will be a consequence in terms of U.S.-Venezuelan relations."

He didn't indicate exactly what the U.S. response would be.

Palmer was nominated by President Barack Obama in June to be the next ambassador to Venezuela, a country that has had strained relations with the U.S. almost from the moment that Chavez, a firebrand socialist, took office nearly 12 years ago. Despite the tense diplomatic relations, Venezuela has remained one of the top five suppliers of crude oil to the U.S.

Shortly after being nominated and before ever stepping foot in Venezuela, Palmer got into hot water with the Chavez government when he made controversial statements to a U.S. senator in a letter that was made public. Palmer said Venezuela's military had "morale and equipment problems," and said officials in the Chavez government have "clear" links to Colombian Marxist guerrillas.

That led Chavez to say in speeches in August and several times since then that Palmer cannot become ambassador to Venezuela. He also said the charges made by Palmer were false and "undiplomatic for a supposed diplomat."

Washington, however, didn't heed Chavez's advice that it pick a new candidate for ambassador and instead continued with its confirmation process of Palmer. Last week, a U.S. official at the State Department said Palmer was likely within days of being confirmed by the U.S. Senate, and said the envoy would then hop on a flight to Caracas to get to work as ambassador.

On Saturday, Chavez said that if Palmer takes a flight to Caracas, authorities at the airport will "grab him," sit him down for a cup of coffee and then send him right back to the U.S. as they wave goodbye.

Sour diplomatic relations between Venezuela and the U.S. have been common ever since Chavez took power in 1999.

Chavez booted former ambassador Patrick Duddy from Venezuela for nearly a year in 2008 to show solidarity with Bolivia after its president, Evo Morales, removed the top U.S. diplomat in Bolivia for allegedly inciting violence. Washington denied the charges from Bolivia, and followed by sending home the envoys of Venezuela and Bolivia in Washington.

Duddy eventually returned to Caracas, but left for good in mid 2010 and the embassy in Venezuela's capital has been without an ambassador since then as it awaited Palmer's confirmation.

The issue over the new U.S. ambassador comes as a separate political spat emerged between the two countries over Chavez's decision last week to ask for emergency powers to legislate by decree for a year, which will effectively silence a newly elected legislature that is less friendly to Chavez than previous groups. Crowley said last week that Chavez "seems to be finding new and creative ways to justify autocratic powers."

Chavez labeled the official's comment as more meddling by the U.S. in his country's internal affairs.

-By Dan Molinski, Dow Jones Newswires; 58-414-120-5738; dan.molinski@dowjones.com