As jobs day dawns, the Fed sweats tension between full employment and prices.

Federal Reserve officials are likely to keep a keen eye on Friday’s employment report, as their two jobs — trying to foster full employment while also keeping a lid on inflation — increasingly prove to be a balancing act.

Jerome H. Powell, the Fed chair, and his colleagues have been pumping $120 billion into markets each month and holding interest rates near zero to keep borrowing costs cheap and credit flowing easily, helping to stoke demand and encouraging employers to expand and hire.

Officials have signaled that they will soon begin to slow the bond purchases — something they could announce as soon as November based on cumulative progress in the labor market, even if the September jobs report isn’t a blockbuster. But they have repeatedly promised to continue supporting the economy with low rates for as long as it needs their help. Deciding when it’s time to pull back that aid could be a trickier judgment call than central bankers had expected.

After years in which inflation climbed very slowly — leaving the Fed with latitude to help push the unemployment rate steadily lower — it has taken off in 2021. The pop has been driven higher almost entirely by pandemic quirks. Strong consumer demand for refrigerators and computers has overwhelmed supply chains at the same time as coronavirus-tied factory shutdowns have delayed parts production. The combination has led to shortages for items as varied as rental cars and washing machines, pumping up price tags.

“This is not the situation that we have faced for a very long time, and it is one in which there is a tension between our two objectives,” Mr. Powell said during a recent public appearance. He later added that “managing through that process over the next couple years, I think, is the highest and most important priority, and it’s going to be very challenging.”

That ramps up attention on each of the Fed’s two targets, full employment and steady inflation that averages 2 percent over time.

Central bank officials are hoping that jobs lost during the pandemic return soon, but progress in recent months has been stop-and-start. Economists think employers probably added about half a million jobs last month, up from a disappointing 235,000 in August.

They are also carefully watching inflation, which came in at 4.3 percent in August. Officials expect today’s price pressures to prove temporary. But it has become increasingly clear that, while the drivers are mainly one-offs, they could linger for months. Shipping routes are struggling to catch up, pandemic outbreaks continue to force factory closures, and now a spike in raw goods prices threatens to keep price gains elevated.

The Fed is closely watching to make sure that longer-term inflation expectations remain at healthy levels. Should consumers and investors come to expect higher inflation, they might change their behavior, creating a self-fulfilling prophesy.

Some key gauges of consumer price outlooks have begun moving up. That raises an unhappy possibility: The Fed might find itself under pressure to lift interest rates and cool off the economy before employment has fully rebounded.

While there is little that a central bank can do to spur better port capacity or more apartments, it could arguably cool off demand by lifting interest rates. With fewer consumers buying condos, couches and lawn furniture, factories, homebuilders and cargo ships might catch up, helping to alleviate cost pressures.

But higher rates would also slow business growth and hiring, trapping the pandemic unemployed on the labor market’s sidelines. That’s why Mr. Powell and his colleagues are counseling patience, hoping to avoid overreacting to a price pop that will peter out.

“They’re always walking a tightrope, but that rope is getting a little bit thinner,” said Nela Richardson, chief economist at the payroll and data company ADP. She expects that the Fed will rein in bond-buying with inflation in mind, but doubts that higher prices will prompt rate increases. Fed forecasts have suggested that those will come next year at earliest.

“I think they’re trying to see past this moment,” she said.