The Federal Reserve should not let signs of an economic slowdown distract from its fight against inflation, according to Mohamed El-Erian. Allianz's chief economic advisor said Thursday on CNBC's " Squawk Box " that the central bank should be looking at a slowing economy, but that inflation should remain the top concern. "Yes, inflation is going to come down at the headline level, but it's not going to come down fast enough given how fast the economy is weakening. And that's going to put the Fed in the same dilemma it's been in the last few months," El-Erian said. "I hope the Fed focuses on getting the inflation genie back into the bottle. The worst outcome is that next year we are in a recession and that inflation has proven very sticky," he said. On Thursday, the Bureau of Economic Analysis released a preliminary GDP reading that showed a decline of 0.9% in the second quarter , coming on the heels of another drop in the first quarter. Two straight declines in GDP is sometimes used as a shorthand definition for a recession, though the National Bureau of Economic Research officially designates recessions using more nuanced criteria. El-Erian said that correctly isolating the start of a recession is less important than noticing the downward trend in the economy. "This is an economy that is weakening at a much faster rate than most people expected. That is the bottom line. Whether we are in a recession or not is not as interesting as the fact that we are weakening really fast," El-Erian said. The comments come after the Federal Reserve hiked interest rates by three-quarters of a percentage point on Wednesday. Fed Chair Jerome Powell said "inflation is much too high" but also said the central bank may slow the pace of hikes at future meetings.