European stocks paused from their recent rally Friday with investors awaiting speeches from major central bankers.

The Stoxx Europe 600 was down less than 0.1% in early trade. Equities had climbed in Europe on Thursday, despite the latest installment in a recent run of weak economic data in the region.

The positive tone continued in the U.S., where the S&P 500 reached a fresh all-time high.

The rally comes ahead of speeches by U.S. Federal Reserve Chairwoman Janet Yellen and European Central Bank President Mario Draghi at the Jackson Hole Economic Policy Symposium later Friday.

Many analysts expect Ms. Yellen to reassure markets that interest rates will stay low for some time, despite Fed minutes this week that showed officials had discussed an earlier hike.

"Markets are arguably pricing in a clearly dovish speech. Should Yellen suggest that the more hawkish [Fed] members are starting to influence her thinking then we could see significant volatility: most likely higher bond yields, lower equities," said analysts at Rabobank.

Safe-harbor bonds gained Friday, pulling U.S. 10-year Treasury yields down to 2.40%, while 10-year German yields fell to 0.98%, slightly above their recent record low.

In currency markets, the euro nudged up 0.1% to $1.3290 against the dollar. The common currency has weakened in recent months as investors expect the ECB to consider fresh easing measures while the Fed moves toward rate hikes.

With alarmingly low inflation in the euro zone, investors will be on the lookout for any hints of new policies from Mr. Draghi.

"Although our base case scenario remains for no change of ECB stance, an unexpected shift in message cannot be ruled out. At the very least we suspect Draghi will be cautious not to stand in the way of the recent depreciation in the euro," said currency strategists at BNP Paribas.

In commodities markets, gold was up 0.4% at $1,280.60, while Brent crude oil was down 0.2% at $102.43 a barrel.

Write to Tommy Stubbington at tommy.stubbington@wsj.com

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