The European Union is asking member states to "respond favourably" to an official plea from the Syrian government, signalling the potential for a substantial shift in the bloc's dealings with Damascus as the scale of the catastrophe grows.

The government of Syrian President Bashar al-Assad made an official plea to the EU for help on Wednesday.

The European Union was swift to dispatch rescue teams to Turkey after the massive earthquakes struck the country on Monday, close to the border with Syria.

But it initially offered only minimal assistance to Syria through existing humanitarian programmes because of EU sanctions imposed since 2011 on the government of President Bashar al-Assad. The sanctions were in response to his brutal crackdown on protesters, which spiralled into a civil war.

The US has ruled out working with Syria and has not indicated a change in its sanctions policy.

EU signals it is ready to work with Assad government on aid