Stocks fall again as investors watch Ukraine developments cautiously.

Stocks fell again on Friday, capping another down week as continued concerns about a Russian invasion of Ukraine added to Wall Street’s already-fragile sentiment.

The S&P 500 fell 0.7 percent, bring its losses for the week to 1.6 percent. The Nasdaq composite fell 1.2 percent on Friday.

The week’s selling came amid mixed messages about the situation in Ukraine. American officials said on Friday that Russia had amassed as many 190,000 troops near the Ukrainian border, raising concerns about an invasion that could hit the global energy supply and add to inflation. At the same time, President Biden’s secretary of state, Antony J. Blinken, accepted an invitation to meet next week with the Russian foreign minister, Sergey V. Lavrov.

With stock markets in the U.S. set to be closed on Monday for the Presidents’ Day holiday, the uncertainty gave investors a good reason to back away.

“Sensitive investors will be fearful about holding on to risk over a long holiday weekend,” said Christopher Harvey, head of equity strategy at Wells Fargo Securities.

Ukraine isn’t Wall Street’s only concern these days. The S&P 500 has fallen for five of the first seven weeks of the year, with most of those losses driven by worry over inflation and rising interest rates and the threat they pose to corporate profits and the American economy.

The index is down 9.3 percent from its Jan. 3 high, approaching a critical threshold called a correction — a drop of 10 percent from a record that is seen, on Wall Street at least, as confirmation that sentiment toward stock investments has changed substantially.

The situation in Ukraine does tie in with concerns that have driven the sell-off this year. Russia is a big oil producer and Europe’s largest supplier of natural gas, and an invasion of Ukraine would almost certainly push already costly energy prices higher.

Crude oil prices, which have already climbed to levels not seen since 2014, were volatile on Friday.

Brent crude, the global benchmark, rose slightly, to $93.54, after earlier falling more than 2 percent. West Texas Intermediate, the U.S. benchmark crude, fell 0.8 percent to $91.07 a barrel, after earlier having dipped below $90 a barrel.

Analysts said oil traders were also responding to reports that talks to revive a nuclear deal with Iran were making progress, a development that could bring tens of millions of barrels of oil to the market.

With inflation in the U.S. already running at the highest rate in four decades, a spike in energy prices or any impact on the already frayed global supply chain would only make matters worse. Investors were already worried that the Federal Reserve would raise interest rates too aggressively as it looks to contain prices, and any spillover from a Russia-Ukraine conflict could increase urgency for the central bank.

This week, several Fed officials addressed the need for it to take action soon.

Lael Brainard, a Fed Governor, said on Friday that she anticipated it would be “appropriate” to “initiate a series of rate increases” at the Fed’s next meeting in March.

Policymakers “will turn next to balance sheet runoff” — allowing some of the $9 trillion in bonds and other assets the central bank has accumulated to mature without reinvestment — she said at a forum held by the University of Chicago Booth School of Business in New York. That could happen “probably in coming meetings,” she said, adding that, together, “those things will bring the inflation down over time.”

And Charles Evans, the president of the Federal Reserve Bank of Chicago, said during a speech on Friday that “our present monetary policy setting is wrong-footed against the current, sharp increase in inflation.”

Yields on U.S. 10-year Treasury notes fell to about 1.93 percent, from about 1.97 percent, another sign that investors were seeking out relatively safe investments. Bond yields fall when their prices rise.

Jeanna Smialek contributed reporting.