FRANKFURT, July 25 (Xinhua) -- The European Central Bank (ECB) on Thursday kept key interest rates for the euro area unchanged but revised forward guidance to open doors for possible monetary policy easing.

The central bank said in its latest policy decision statement that it expects the key interest rates to remain "at their present or lower levels" at least through the first half of 2020, a slight shift from the June 6 statement that used the wording "at their present levels" only.

The central bank underlined the need for "a highly accommodative stance" of monetary policy for a prolonged period of time since "inflation rates, both realised and projected, have been persistently below levels that are in line with its aim."

It will stand ready to "adjust all of its instruments, as appropriate, to ensure that inflation moves towards its aim in a sustained manner," it added.

The ECB also said it has tasked relevant Eurosystem Committees with examining mitigating measures "such as the design of a tiered system for reserve remuneration", and options "for the size and composition of potential new net asset purchases," which is largely in line with market expectations.

The eurozone base interest rate will remain at 0.00 percent, with the marginal lending rate and deposit rate staying at 0.25 percent and minus 0.40 percent respectively, according to the central bank.