The government of Turkey has agreed to a total ban on capital punishment.
It is being seen as an important move towards acceptance into the EU.
The European Commission said Ankara's latest move was a 'significant step on its way to becoming a fully fledged democracy'.
Its envoy to the Council of Europe signed a European Convention protocol abolishing the death penalty in all circumstances, including during wars.
The Turkish parliament had already voted to abolish the death penalty in peacetime in August of 2002.
Analysts say the signing of the protocol is part of an extensive programme of human rights reforms being demanded by the EU before it will consider granting membership to Turkey.
The protocol must be ratified by the Turkish parliament.
The EU is expected to decide at the end of the year whether to open entry negotiations with Ankara.
