LUSAKA, Jan. 30 (Xinhua) -- Former Zambian foreign minister on Tuesday officially announced that he will challenge President Edgar Lungu for the country's presidency in the 2021 general elections.

Harry Kalaba, who resigned as foreign minister in January 2018 over rife government corruption, said he will run for president as a candidate from an opposition political party, the Democratic Party.

He told reporters during a press briefing that he was expelled from the ruling party not because of any gross misconduct but because of criticizing high-level government corruption.

He said he will not re-contest as a lawmaker for a constituency in the northern part of the country where he was a Member of Parliament (MP) under the ruling party because he wanted to direct his energies towards mobilizing support for his 2021 presidential bid.

"I do not wish to challenge the decisions of the PF (the ruling party Patriotic Front) in the courts of law, I will spare the courts the drama of adjournments," Kalaba said.