A spokesman for South Sudanese rebels says rebel leader Riek Machar has not returned to the capital as planned because the government did not clear a flight for a top general.

Rebel spokesman William Ezekiel said Tuesday that he did not know when Machar would return to Juba.

He said the government demanded the plane meant to carry General Simon Gatwech from Ethiopia receive prior clearance to use South Sudan airspace.

Government spokesman Michael Makuei said they denied flight clearance because the rebels wanted to bring between 260 and 500 rebel troops with Gatwech, more than what had been agreed.

Machar was initially expected to return Monday to be sworn in as vice president under President Salva Kiir after more than two years of civil war.