Finance undersecretary Arturo Herrera told reporters after Urzua's resignation that Lopez Obrador would make an announcement on the replacement shortly, adding that he will stay at the ministry, without elaborating.
Mexican President Andres Manuel Lopez Obrador said on Wednesday that former Finance Minister Carlos Urzua, who resigned on Tuesday, had differences with the president's chief of staff and businessman Alfonso Romo, among other issues.
"He is not happy with the decisions we are taking", Lopez Obrador said about Urzua in a video on Facebook, standing alongside Herrera after the minister's resignation.More news: Countries restricting media freedom must pay price: UK's Hunt
Following the news, the Mexican peso lost nearly two percent, dropping from 18.90 to 19.27 against the USA dollar.
Urzua cited "extremism" as a reason he felt forced to quit.
Investors have anxious about Lopez Obrador's policy direction since he cancelled a major airport project before taking office, and the government has clashed with businesses on a number of occasions.More news: Two dozen deaths in tribal violence in Papua New Guinea
"I don't see a recession around the corner".
Despite his comments on fiscal discipline, Herrera made clear he was also on board with Lopez Obrador's expansive infrastructure plans, and vowed to stay in the post until asked to leave.
"We can't put old wine in new bottles", he added.More news: Penguins center Matt Cullen retires after 21 seasons | AP sports
"We believe there will be economic growth, that we will progress in the country by fighting corruption and ... with a policy of austerity", the president said.