The Zanu-PF politburo met on Wednesday in Harare to discuss the plan set out this week by the Southern African Development Community (SADC) following marathon talks at a summit in Pretoria.
"Zanu-PF is fully behind this resolution and the politburo has endorsed it," party spokesperson Nathan Shamuyarira said in the government mouthpiece Herald newspaper after the meeting.
"President Mugabe is now expected to start rolling out the process to implement the agreement according to recommendations of the regional bloc."
Opposition leader Morgan Tsvangirai has yet to endorse the deal – under which he would become prime minister – warning that it could be derailed by disputes over key ministries, particularly the home affairs post.
His Movement for Democratic Change (MDC) is set to meet Friday to decide whether to accept the deal and form a unity government with Mugabe by February 13.
He has told South African media that negotiators would meet on Thursday in Harare to try to settle their remaining differences.
March’s first round presidential election, in which Tsvangirai placed first but did not win an outright majority, was followed by a brutal wave of political violence.
Tsvangirai pulled out of the run-off, citing violence against his supporters, leaving Mugabe to declare a one-sided victory in June.
Since then Zimbabwe has plunged deeper into crisis amid massive unemployment, with half the population dependent on food aid.
The nation’s economy has crumbled under stunning hyperinflation, leaving basic infrastructure like hospitals and sanitation in shambles as a cholera epidemic sweeps the country, killing more than 3 000 people.
Mugabe and Tsvangirai signed a unity accord in September, but have remained deadlocked over control of the key home affairs ministry, changes to the constitution and MDC allegations that its members have been abducted.