US pre-open: Stocks looks set for more losses ahead of Fed speeches

As of 1220 BST, Dow futures were down 0.35%, while S&P 500 and Nasdaq futures had those indices opening 0.37% and 0.50% lower, respectively.

The Dow Jones closed 115.98 points lower on Monday after the previous week's strong jobs data dampened expectations that the Federal Reserve would cut interest rates by 50 basis points when rate-setters in the US next met at the end of July.

With interest rates in mind, investors were waiting on speeches from St.Louis and Atlanta Fed Presidents, James Bullard and Raphael Bostic, at 1510 BST and 1910 BST, respectively.

Powell was also providing the opening remarks at a Boston Fed conference on Tuesday but, as expected, made no references to monetary policy ahead of his semi-annual testimony to the House Financial Services committee on Wednesday.

Coming just a few days after a much stronger-than-expected jobs report raised questions about the central bank's interest rate policy, market participants were keen for fresh insights into Fed policymakers' most current thinking.

Oanda's Craig Elam said: "I'm not convinced that investors will get the message they're after this week, with Powell in the past having been very conservative in his interest rate rhetoric. The central bank has left the door open to cuts without committing to anything and I expect to get more of the same.

"A cut in July will be difficult to dodge given current market pricing but Powell may use the opportunity to manage expectations beyond the meeting. How successful he'll be is another thing as investors don't appear to want to hear it and may instead continue to apply the pressure going into the September meeting."

Elsewhere, the row between the UK and US over leaked diplomatic cables describing Donald Trump as "inept" escalated overnight as the president said he would not work with British ambassador Kim Darroch.

In a series of typically bombastic tweets, Trump also slammed outgoing UK Prime Minister Theresa May's handling of Brexit, calling it a "mess" and claiming she had ignored his advice on the subject.

On the data front, the National Federation of Independent Business' small business optimism index for June dipped to 103.3 - down from the 105.0 recorded in May and marginally above consensus estimates of 103.1.

Pantheon Macroeconomics' Ian Shepherdson said the most important number in the report was selling prices, which rocketed to 17 from 10.

"The index usually is responsive to gasoline prices, which dipped last month, pointing to a two-point dip. Adjusted for the impact of gas prices, this is the highest reading for the selling price measure since November 2006, and it is consistent, if sustained, with core CPI inflation rising to 2.7% by next spring," he said.

"We assume this jump reflects the increase in tariffs on Chinese imports in May, from 10% to 25%, so we doubt it will reverse anytime soon."

The headline index, meanwhile, was pulled down by six-point drops in sales expectations and "good time to expand", and a four-point fall in capex plans.

Still to come, JOLTS job openings figures for May will be posted at 1500 BST.

In corporate news, PepsiCo and Levi Strauss will post their latest figures.