Wall Street stocks mostly fell Friday amid weakness in some semiconductor shares as markets weighed the latest developments in the ongoing war between Iran and Israel.

Markets rose after President Donald Trump's remarks Thursday on the Middle East allowing for up to two weeks before possible US military action against Iran.

But on Friday afternoon, Trump expressed doubt that European powers would be able to help end the Iran-Israel war, telling reporters "Europe is not going to be able to help in this."

The Dow Jones Industrial Average finished up 0.1 percent at 42,206.82.

But the broad-based S&P 500 shed 0.2 percent to 5,967.84, while the tech-rich Nasdaq Composite Index fell 0.5 percent to 19,447.41.

Analysts pointed to a pullback in some chip companies following a Wall Street Journal report that said the United States could revoke waivers used by some companies to access US technology in China.

Asked about the matter, a Commerce Department spokesperson told AFP that chipmakers will still be able to operate in China.

"The new enforcement mechanisms on chips mirror licensing requirements that apply to other semiconductor companies that export to China and ensure the US has an equal and reciprocal process," the spokesperson added.

Adam Sarhan of 50 Park Investments described the market as on edge in anticipation of new headlines on trade actions or the Middle East.

"We have a situation where tensions in the Middle East missiles are still firing, there's no ceasefire and there's a fear that the US may be involved," Sarhan said.

In light of uncertainty on Iran and other areas, "investors are de-risking, they're selling stocks ahead of the weekend," Sarhan said.

Fed governor Christopher Waller told CNBC that central banks should "look through tariff effects on inflation" and focus instead on the underlying trend in price increases.

The Fed earlier this week voted to keep interest rates unchanged, as Fed Chair Jerome Powell said the central bank could wait to see if Trump's tariffs revive inflation.

Among individual companies, Kroger jumped nearly 10 percent after the supermarket chain raised its sales forecast. However the company refrained from lifting other projections, saying the macroeconomic environment remains "uncertain."

CarMax surged 6.6 percent after reporting a jump in quarterly profits as the company's CEO pointed to a "very large and fragmented" used car market that "positions us to continue to drive sales, gain market share and deliver significantly year-over-year earnings growth for years to come."