10 things you need to know before the opening bell

Here is what you need to know.

No country will be excluded from Trump's tariffs. "As soon as you exempt one country, you have to exempt another country, and so ... it's a slippery slope," White House National Trade Council director Peter Navarro told CNN.

China is threatening to retaliate. "China does not want a trade war with the Untied States, but we will absolutely not sit idly by and watch as China's interests are damaged," China's National People's Congress spokesperson Zhang Yesui told the BBC.

Trump's tariffs 'could not have come at a worse time' for anyone planning to buy a home. "Given that home builders are already grappling with 20 percent tariffs on Canadian softwood lumber and that the price of lumber and other key building materials are near record highs, this announcement by the president could not have come at a worse time," Randy Noel, chairman of the NAHB, said in a statement.

China sets a growth target of 6.5% for 2018. The announcement was made by Chinese Premier Li Keqiang in an address to the National People's Congress.

Italy is facing a hung parliament after Sunday's election. The 5-Star Movement is predicted to have won one-third of all votes cast, up from 25% in the previous election, Reuters reports.

AXA buys Bermuda-based XL in insurance mega-deal. AXA has agreed to pay $15 billion, or $57.60 per XL share, in a deal that will create a world leader in property and casualty insurance, Reuters says.

Evidence is piling up for the location of Amazon's HQ2. Hints the company has dropped - both on purpose and inadvertently - are starting to point towards Washington, DC.

Black Panther wins the box office for a 3rd straight week. The latest Disney/Marvel sensation took in an estimated $65.7 million, according to boxofficepro, raising its three-week total to more than $500 million and making it the highest-grossing Marvel Cinematic Universe title of all time.

Stock markets around the world trade mixed. Hong Kong's Hang Seng (-2.28%) was hit hard in Asia and Germany's DAX (+0.92%) is out front in Europe. The S&P 500 is set to open down 0.16% near 2,687.

US economic data flows. Markit US Services PMI and ISM non-manufacturing will be released at 9:45 a.m. ET and 10 a.m. ET respectively. The US 10-year yield is down 2 basis points at 2.84%.