Ukrainian President Volodymyr Zelenskyy said the United States has set a June deadline for Ukraine and Russia to reach an agreement to end the nearly four-year war.
U.S.-led efforts to end Europe's deadliest conflict since World War II have stepped up a gear in recent weeks, but Moscow and Kyiv remain at odds over the key issue of territory.
Russia, which occupies around 20 percent of its neighbour, is pushing for full control of Ukraine's eastern Donetsk region as part of any deal and has threatened to take it by force if talks fail.
But Ukraine says ceding ground will embolden Moscow and so it will not sign an agreement that fails to deter Russia from invading again.
"The United States has proposed for the first time that the two negotiating teams, Ukraine and Russia, meet in the United States, probably in Miami, in a week's time," Zelenskyy told reporters in comments made public early Saturday.
"They say that they want to do everything by June," he added.
The U.S. has mediated two rounds of negotiations between the two sides in Abu Dhabi since January, brokering a major prisoner exchange but failing to reach a breakthrough on territory.
Both Moscow and Kyiv said talks have been difficult.
