Justice Minister Vesna Skare-Ozbolt told a news conference on Monday Generals Mladen Markac, 48, and Ivan Cermak, 54, would go to The Hague by the end of this week.
They have been charged with crimes against humanity and violations of the laws and customs of war for atrocities in a 1995 government offensive against Serb rebels.
Cooperation with the tribunal is a key condition for Zagreb to start European Union entry talks next year. Failure to hand over indictees would almost certainly block Zagreb's path, damaging investor confidence in the former Yugoslav republic.
"The generals received the indictments and immediately expressed readiness to appear before the tribunal as soon as possible," Skare-Ozbolt said.
"The government is convinced that the tribunal will also welcome the decisions ... and will temporarily release them before the start of their trials," she added.
The generals will fly to the tribunal's seat in the Netherlands on Thursday and enter their pleas in court on Friday, their lawyers told state radio, adding they would ask for their release from custody after that.
Monday's surrender could intensify the spotlight on neighbouring Serbia, whose newly appointed conservative prime minister, Vojislav Kostunica, wants Serb suspects tried at home and considers extradition to The Hague "not a priority".
For Belgrade, an assessment of non-compliance by the United States at the end of March could mean a financial aid cut-off.
Pledged to surrender
Both Croatian generals have been questioned by tribunal investigators in the past and pledged to surrender if charged.
According to the indictment, published on Monday, Cermak and Markac participated in a "joint criminal enterprise" to forcibly and permanently remove the Serb population and plunder, damage or destroy Serb property.
"Ivan Cermak and Mladen Markac had the power, authority and responsibility to prevent or punish serious violations of international humanitarian law committed by Croatian forces during and after Operation Storm," the indictment said.
Cermak, a wealthy oil businessman, ran the former rebel stronghold of Knin after its capture. Markac commanded special police units that combed the area.
Croat President Stjepan Mesic told local media he could testify in Cermak's defence, saying Cermak had been in charge of restoring civilian life in the Knin area and not of military activities. Mesic met Cermak at the time when visiting the area as an opposition politician.
Fugitive General Ante Gotovina was indicted over the same atrocities in 2001, but remains in hiding. Diplomats believe his unresolved status could continue to weigh on Croatia's EU attempt.
The Netherlands and Britain stopped a ratification process for an EU associate membership accord with Zagreb last year, citing patchy cooperation with the tribunal.
There had been fears the election victory of Croatia's formerly hardline nationalist HDZ party last November would throw cooperation into reverse.
"With this the government is showing commitment in meeting all its international obligations including full cooperation with the tribunal," Skare-Ozbolt said.