This is reported by The Washington Post, citing sources.
"Negotiations with Russia on the renewal of the cease-fire agreement, which discussed the joint withdrawal of US and Iranian troops, largely collapsed ... when Bolton decided that the US troops would not leave until all Iranian forces left Syria," reported in the text.
On March 4, it was reported that the heads of the Russian and US General Staffs, Valery Gerasimov and Joseph Dunford, discussed issues of missile defense, as well as interaction in Syria.