He told a news conference in Johannesburg he would meet Zimbabwean President Robert Mugabe and Kgalema Motlanthe, president of neighbouring South Africa, this week to discuss the stalled power-sharing deal signed in September last year.
"I still believe that a political agreement offers the best means of preventing Zimbabwe from becoming a failed state. I am committed to forming a new inclusive government in Zimbabwe and all I lack is a willing partner," Tsvangirai said.
The Movement for Democratic Change leader said he will return to Zimbabwe on Saturday for the first time since November last year.
The agreement is seen as a chance to rescue Zimbabwe, a once prosperous country whose economy is now in ruins.
A cholera epidemic which has killed over 2,000 people has added to the humanitarian crisis in the country.
Mugabe, in power since independence from Britain in 1980, has resisted Western calls to step down.