KIEV, Ukraine (AP) -- The Ukrainian government will restart cease-fire negotiations with pro-Russian insurgents in the country’s east only once the rebels lay down their weapons, the defense minister said Tuesday

Valery Heletey’s statement, posted on the Defense Ministry website, comes amid growing confidence among government forces after they drove the insurgent militia from their stronghold of Slovyansk.

Last week, Ukrainian President Petro Poroshenko promised cease-fire talks no later than that Saturday, but a series of military successes by the Ukrainian army may have changed minds in Kiev. Instead, on Saturday, Ukrainian troops routed the rebels in Slovyansk, forcing hundreds of militants to regroup in the regional capital, Donetsk -- a rare and significant victory for Ukraine, which has often appeared helpless in the face of the spreading insurgency.

A 10-day cease-fire that ended in late June was punctuated by frequent clashes and provided no progress in reaching a negotiated settlement. More than 400 people have died and thousands have fled their homes after a nearly three-month-long standoff between the rebels and the new authorities in Kiev, who came to power after the ex-president’s ouster in February.

Rebels in Ukraine and nationalists in Russia have called for the Kremlin to protect the insurgents, but Russian President Vladimir Putin has so far made no comment on the rebels’ defeat in Slovyansk, while state media and other officials have downplayed the loss. Putin may be wary of more sanctions being imposed by the West, which slapped visa bans and financial sanctions on Russia’s top officials for their role in annexing the Black Sea region of Crimea in March.