WASHINGTON/MEXICO CITY (Reuters) - Mexico and Argentina have delayed a key meeting of the Inter-American Development Bank until after the Nov. 3 U.S. election, delivering an early setback to plans by the bank’s new U.S. chief to install vice presidents from smaller countries.Wednesday’s meeting of the IDB’s 14-member board was abruptly postponed at the request of Argentina and Mexico, the IDB press office said, adding that a majority of the board backed the three nominees from Honduras, Ecuador and Paraguay. No new date has been published on the bank’s website. One source close to the process said the two countries could in theory delay the vote for three months under the bank’s rules. Mexico and Argentina want to wait until after the U.S. election before voting on the basis that support for IDB President Mauricio Claver-Carone, the first U.S. citizen to head the regional lender, might fade if President Donald Trump loses his re-election bid, said one official familiar with the matter. Both countries had opposed the candidacy of Claver-Carone, a former top adviser to Trump, who took over the helm of Latin America’s main financial institution this month.