FRANKFURT, Germany (AP) — When is a trillion euros not enough? Could be soon, in Europe's shaky economy.

Analysts are already talking about when and how the European Central Bank might extend its 1.1 trillion-euro ($1.2 trillion) stimulus program that has been running for the past six months in an attempt to boost the modest recovery in the 19 countries that use the euro.

They say ECB President Mario Draghi will likely use his news conference Thursday to underline the bank's willingness to increase its efforts, if needed, to push up stubbornly weak inflation or limit any damage from the economic troubles in China.

The stimulus program is slated to run through September 2016, in monthly purchases of 60 billion euros of government and corporate bonds. The effort, called quantitative easing, or QE, pumps newly printed money into the economy. It is aimed at raising a rate of inflation that is so low as to provoke fears about the health of the economy.

Yet the impact of the ECB's program remains unclear.

Despite major tail winds from low oil prices, a weak euro and massive central bank stimulus, the eurozone's economic recovery remains tepid.

On the upside, banks are lending a bit more to companies.

But on the negative side:

— Inflation is stuck at a low 0.2 percent, a sign demand is too weak to drive up prices.

— The latest survey of eurozone business and consumer confidence ticked up in August. But it increased in only 11 of the 19 euro countries. In seven of them, it fell, including the biggest, Germany. One country, Ireland, did not report data.

— Unemployment, at 10.9 percent in July, is edging down only slowly. And huge disparities remain between countries — Germany has a record low rate of 4.7 percent while Greece's is around 25 percent.

— Economic growth was a modest 0.3 percent in the second quarter.

Draghi made it clear at the time the stimulus program was announced in January that it could be extended beyond September 2016 if inflation doesn't convincingly head higher. He may stress that willingness again when he speaks after a Thursday meeting of the bank's governing council. Some, however, aren't ruling out more concrete action at the meeting.

Analysts at financial services group Nomura said they expected the ECB to take no new steps. But they added that "the risk of further ECB action has clearly increased."

ECB action, now or at coming meetings, could mean an extension of the stimulus program out to March 2017, Nomura analysts Nick Matthews and Norbert Aul wrote. They said the ECB could also make smaller tweaks, such as reviewing technical limits on its bond purchase that would open the way for expanding them.

Pushing newly printed money into an economy can raise inflation, make credit more available and in theory support growth and jobs. It has been tried by the U.S. Federal Reserve, the Bank of England and the Bank of Japan.

The Fed has already finished its bond-purchase stimulus and is weighing whether to start tightening monetary policy with an interest rate increase in September.

More ECB stimulus — or the expectation of it — could help keep the euro's exchange rate down against the dollar and help exports, one of the most important effects of bond-buying programs.

One guide to the ECB's future stance could be the new inflation projections published Thursday. Analysts expect them to be lowered from the June expectations for 0.3 percent this year and 1.5 percent next year.

The June inflation projections were based on oil prices of $63.80 per barrel this year and $71 next year measured by the international Brent benchmark price. That's clearly out of date: Brent crude traded around $49 this week.

No change is expected in the bank's benchmark interest rate, held at a record low of 0.05 percent since Sept. 10, 2014. The bank has said that's as close to zero as it can go.