Bloomberg reports

ECB

The report says that policymakers at the ECB anticipate using an interest rate cut as their first stimulus move if they need to act again to boost inflation, citing three ECB officials on the matter. Adding that they would much prefer that than to resume asset purchases.

With regards to the timing to introduce said stimulus, the officials said that they were open on the timing of any move but says that a Fed rate cut could become a trigger if it threatens to boost the euro.

Although the exchange rate isn't a policy target for the ECB, they have previously noted in the past that it could have an impact on inflation and growth so they wouldn't want to be caught lagging the Fed I reckon.

Update: Money markets have now priced in a 10 bps rate cut by the ECB in September, from December earlier today.