The New Zealand government opposes the tour because of human rights abuses in Zimbabwe. But it has ruled out legislating a ban on the tour or directing New Zealand Cricket (NZC) to cancel it.
International Cricket Council (ICC) chairman Ehsan Mani said in a letter the ICC had rejected the New Zealand government's request to alter its tour schedule but added it recognised governments could apply sporting sanctions.
"Our members accept and respect that where this clear directive is given by a national government, the obligations of the future tours programme will not apply."
A spokesman for New Zealand foreign minister Phil Goff said clarification was being sought from the ICC on what would constitute a clear directive.
"We want to clarify whether a parliamentary motion saying NZC should not tour would be sufficient to give NZC a release," the spokesman said.
Unless NZC can win a release from its tour obligations, it faces a fine of at least two million US dollars and claims from Zimbabwe for lost revenue.
Opposition to the tour has grown in New Zealand as Zimbabwe President Robert Mugabe's government presses ahead with a campaign to demolish shacks and other illegal homes and businesses, leaving hundreds of thousands homeless.
Zimbabwe's first black Test cricketer Henry Olonga arrived in New Zealand Tuesday to support the campaign to cancel the tour, saying the situation in his former country could be likened to apartheid in South Africa.