SAN SALVADOR, Dec 15 (Reuters) - A strong majority of Salvadorans approve of President Nayib Bukele"s government despite controversies over his policies and U.S. sanctions on his cabinet, according to a poll by the investigative unit of local newspaper La Prensa published Wednesday. The findings showed that 85.1% of those surveyed either highly approve or somewhat approve of Bukele, 40, despite some skepticism of his move to make El Salvador the first country in the world to adopt bitcoin as legal currency. He has also largely brushed off accusations from the United States and rights groups of power grabs aimed at weakening democratic institutions. Only around 12% partially or highly disapprove, the poll showed. About 3% of people did not respond to the query. That put Bukele"s approval slightly higher than the 84.9% approval rating of the previous poll in September, though it has dipped modestly since June. "The approval of the president is similar to that of three months ago, and one of the lowest since he began his mandate, but it still remains above the acceptance that his predecessors had in office, for the same time in office," La Prensa said of its poll. Opposition groups in the country and the White House have harshly criticized Bukele for his combative style of government, which included the firing in May of the judges on the constitutional panel of the Supreme Court, as well as the then-attorney general. Washington last week sanctioned members of Bukele"s cabinet for alleged links to corruption cases and gang negotiations. Bukele has denounced the sanctions. Hundreds of Salvadorans protested on Sunday against Bukele and his allies, accusing the president of trying to consolidate power. "I don"t believe anything by (La Prensa), but for them to say 85.1%... the approval they report is even higher than it was three months ago. So the marches were useless?" Bukele said on Twitter about the poll. The poll also showed that crime and insecurity, gangs, the economy and unemployment were the top concerns of those surveyed. The poll, conducted between Nov. 24 and 29, interviewed 1,520 people from all over the country and has a margin of error of plus or minus 2.6%.