One of Europe's poorest nations, the ex-Soviet state has been in political chaos since a general election in February failed to give a clear majority to any party.
On Saturday, parliament approved a new government based on an unprecedented alliance between pro-Russian and pro-European forces.
The Socialist Party of then-president Igor Dodon agreed to work with the pro-European ACUM alliance and freeze out the previously ruling Democratic Party, led by the powerful oligarch Vlad Plahotniuc.
The parties said the state was being held "captive" by oligarchs, adding that Moldova was "wallowing in corruption".
However the coalition was formed after the Constitutional Court ruled Friday that fresh elections should be held.
On Sunday, the court suspended president Dodon and appointed Pavel Filip, the former prime minister from the Democratic Party, as interim leader.
Filip said Dodon had been suspended because he had refused to sign off on parliament's dissolution.
The new acting president immediately called a snap vote for 6 September.
The European Union urged "calm and restraint" and said in a statement it was "ready to work with the democratically legitimate government".