KABUL (Reuters) - Afghan Interior Minister Amrullah Saleh stepped down from his post on Saturday in order to run for the vice-presidency alongside President Ashraf Ghani who plans to bid for a second term in July’s election.

FILE PHOTO: Amrullah Saleh, Afghanistan's former intelligence chief, speaks during an interview in Kabul February 15, 2012. REUTERS/Mohammad Ismail

The former top security official told Reuters by phone that he had resigned and two political sources said he would join Ghani’s team.

“He wants to contest for the post of vice-president,” said a source from the presidential palace in Kabul.

Saleh, who commands strong support among Afghanistan’s minority ethnic Tajiks, had been expected to oppose Ghani in the election, which has been pushed back from April to July.

Under Afghanistan’s electoral system, all members of government except the president and vice president must step down in order to run for office.

In December, Ghani appointed Saleh, a former security official and an uncompromising opponent of the Taliban, to his government in a bid to secure the support of former opponents for a second term.

Afghan forces have been dying in record numbers in the face of a resurgent Taliban. U.S. President Donald Trump is considering slashing the number of American troops in the country in half. However the White House says there has been no official order.

Afghanistan’s presidential race is now in full swing, with several former officials and politicians lining up to challenge Ghani who is expected to register his candidacy for a second term on Sunday.

Former warlord Gulbuddin Hekmatyar, whose fighters killed thousands in Kabul during the bloody civil war of the 1990s, joined the presidential race on Saturday.

The political landscape is dominated by ethnic loyalties, personal alliances and often unstable coalitions between powerful regional leaders.

“Ghani’s decision to include Saleh in his presidential bid reflects how alliances are being formed quickly and ideological differences are being ignored,” said a Western diplomat in Kabul.