Phelekezela Mphoko will be acting president in Mugabe’s absence.
The commemorations will be held on Saturday but Mugabe asked to stay in Moscow for a little longer, his spokesman confirmed Thursday.
“Ordinarily, we would’ve returned home after two days but the President has asked for elongation,” George Charamba told state media.
The veteran leader has come under attack from opponents for constantly flying abroad even as the government admits it has no money and the economy struggles to recover.
Mugabe is chairman of the African Union and the regional SADC grouping.
Charamba said it was in that capacity the 91-year-old was invited to Moscow.
“This is a commemoration of the 70th anniversary of victory over Nazism. It’s a world event and the President is going there representing Africa,” said Charamba.
The government has also been looking to China and Russia for a financial lifeline as well as investment to help turn the country’s economy around.
Charamba said Mugabe would stay in Moscow a little longer to engage local business and the government over trade and investment.
“That’s our main focus, apart from the ceremonial side of this visit,” he said.
“We intend to engage Russian business leaders and get some new and old deals finalised. There’s a lot of on-going contact between our ministers and the Russians.”
Russian foreign minister Sergei Lavrov visited Harare last September and sealed a deal for the development of a US$3 billion platinum mine at Darwendale.