U.S. stock index futures point to a higher open on Wall Street on Monday, ahead of the publication of the Manufacturing Purchasing Managers' Index, or PMI, as fears about the U.S. Federal Reserve's decision to wind down stimulus measures make way for concerns regarding the debt ceiling, which is expected be hit on Oct. 1.

Futures on the Dow Jones Industrial Average were up 0.27 percent, while futures on the Standard & Poor's 500 Index were up 0.14 percent and those on the Nasdaq 100 Index were up 0.37 percent.

After the Fed’s decision to refrain from reducing the pace of its $85 billion-a-month bond-buying program last week, investors have switched attention to a potential repeat performance of a struggle between the Republican-controlled House of Representatives and the Democratic-majority Senate on the debt ceiling and the upcoming federal budget.

“It appears a government shutdown is ripe,” Mark Luschini, chief investment strategist at Janney Montgomery Scott, told MarketWatch. “Investors need to be cautious about that.”

On Monday, investors are also expected to focus on the flash Manufacturing PMI for the month of September published by Markit Economics and scheduled to be released at 9 a.m. EDT. The index, which measures the activity level of purchasing managers in the manufacturing sector, is expected to show a reading of 54 in September, up from 53.10 recorded in August.   

In Europe, markets traded flat to lower on Monday despite the flash services PMI and the composite output index for the 17-nation euro zone posting a 27-month high in September. The Stoxx Europe 600 index and France's CAC-40 were trading flat while London’s FTSE 100 was down 0.26 percent and Germany's DAX-30 was down 0.09 percent.

In Asia, markets were mixed, after a better-than-expected manufacturing survey report from China showed that the preliminary reading of HSBC's manufacturing PMI for September beat expectations to climb to a six-month high.

The Shanghai Composite index rallied 1.33 percent, while Hong Kong’s Hang Seng Index -- which resumed trading in the afternoon session after a storm forced it to close in the morning session -- ended down 0.56 percent. Australia’s S&P/ASX 200 ended down 0.46 percent; South Korea’s KOSPI Composite index added 0.19 percent while India’s BSE Sensex was trading down 1.86 percent in late-afternoon trade. Japan’s Nikkei remained closed for a public holiday.