JOHANNESBURG (Reuters) -South African President Cyril Ramaphosa said on Friday he expected his party's main coalition partner, the Democratic Alliance (DA), to propose a replacement for the DA deputy trade minister he fired earlier this week.

Ramaphosa's decision to sack Andrew Whitfield over an unauthorised trip to the United States drew an angry response from the DA on Thursday, the latest public spat between the two biggest parties in the multi-party government.

The president said in a statement that Whitfield had violated established practice for members of the national executive.

"Prior to the removal of Mr Whitfield, I informed Minister John Steenhuisen as the leader of the Democratic Alliance... and (told Steenhuisen) that I expect him to present to me for approval a replacement," Ramaphosa said.

The DA has called a press conference for Saturday to say what it will do next.

Political and financial analysts expect the Government of National Unity coalition to hold, despite the often-fractious relationship between Ramaphosa's African National Congress (ANC) and the DA.

The former liberation movement and the pro-business DA are far apart ideologically and have clashed over this year's budget and policies to address racial inequality.

But the ANC needs the support of at least one other big party to pass legislation, and the DA wants to show voters it can make a difference in the cabinet portfolios it secured by teaming up with the ANC.

Steenhuisen gave a speech in parliament on Thursday calling on Ramaphosa to fire corruption-implicated ANC officials in his cabinet instead of removing Whitfield, threatening unspecified consequences if Ramaphosa did not do so.

Ramaphosa said on Friday he would not yield to threats.

(Reporting by Sfundo Parakozov and Alessandro Parodi;Editing by Alexander Winning and Gareth Jones)