U.S. stock index futures slid on Thursday on the last day of a dismal first-half of the year on worries that central banks determined to tame inflation will hamper global economic growth.

Fears over slowing growth and surging prices have rippled through markets, with central bank chiefs across the world prioritizing on steps to lower a well-entrenched inflation at all costs.

Federal Reserve Chair Jerome Powell has vowed to not let the U.S. economy slip into a "higher inflation regime", even if it means raising interest rates to levels that put growth at risk.

The S&P 500 index was on track to end the first half of the year with the biggest percentage drop since 1970, while the Nasdaq Composite was set for its largest declines ever during the same period.

The Dow Jones Industrial Average was set for its biggest January-June percentage drop since the financial crisis, and all the three main indexes are bound to post their second straight quarterly declines, for the first time since 2015.

Fed policymakers in recent days have set expectations for their second consecutive 75 basis point interest rate hike in July even as economic data painted a dour picture of the American consumer.

"It does seem like the pessimism has reached some kind of peak and it certainly is understandable given readings on inflation and slowdown in consumer spending and the economy," said Josh Wein, portfolio manager at Hennessy Funds.

Large-cap growth stocks including Microsoft Corp, Apple Inc, Amazon.com Inc and Tesla Inc fell between 1.3% and 1.7% in premarket trading, leading declines for the day.

A Commerce Department report showed core personal consumption expenditure price index in May was slightly below expectations, although consumer spending rose less than expected.

At 8:40 a.m. ET, Dow e-minis were down 330 points, or 1.06%, S&P 500 e-minis were down 44.75 points, or 1.17%, and Nasdaq 100 e-minis were down 145.75 points, or 1.25%.

Heading into the second half of the year, bruised markets will continue to focus on inflation, unemployment and interest rate increases along with their impact on corporate earnings.

"Earnings growth has certainly shown us that there's been margin pressure which makes sense in an inflationary environment such that we're in," Wein said.

Drugstore chain Walgreens Boots Alliance Inc shed 2.4% as its quarterly profit plunged 76%, hurt by its opioid settlement with Florida and a decrease in U.S. pharmacy sales on waning demand for COVID-19 vaccinations.

Spirit Airlines Inc rose 1.1% after the budget carrier deferred a shareholder vote on Frontier Group Holdings Inc's merger offer until next week.