In a statement on Monday, the White House said, "the United States officials conveyed President Donald J. Trump's clear goal for achieving a fair trading relationship with China. The delegations will now report back to receive guidance on the path forward."

There were expectations that U.S. Commerce Secretary Wilbur Ross could have returned home from weekend meetings with Beijing's commitments to purchase U.S. energy and agricultural products, but Ross left China without announcing new details for a deal.

The Trump administration last week turned trade threats into action by slapping tariffs on steel and aluminum from Canada, Mexico and Europe, all of which have retaliated and are fighting the U.S. move at the World Trade Organization. The heads of Canada, Japan, German, France, the U.K. and Italy will all be in attendance at the G-7 summit in Quebec Friday, and all have first-hand experience with Trump tariffs. Trump meets President Shinzo Abe of Japan on Thursday ahead of the Friday summit.

U.S. trade negotiations seem to have gotten even stickier, as talks between the U.S. and China appear to lack any new breakthroughs and President Donald Trump gets set to meet an unhappy group of world leaders at the end of the week.

The U.S. last week said it would proceed with 25 percent tariffs on $50 billion in Chinese goods, with a final list of imports to be announced June 15. China's Foreign Ministry Monday said it was open in principle to talks with the U.S. but said any trade and business deals with the U.S. would be void if Washington implemented tariffs.

"I think we're at a real low point," said Greg Valliere, chief global strategist at Horizon Investment. "This has been a pretty bad stretch… I do feel pretty strongly about trade, that it's going to get worse before it gets better."

But even so stocks rallied Monday on strong U.S. growth prospects, ignoring the backdrop of difficult trade developments. The tariffs and trade friction is not expected to have much impact on the broader economy, but trade experts say they could create job losses in some sectors reliant on metals and drive prices higher for consumers.

"Markets are focused on an accelerating U.S. economy," notes Dan Clifton, head of policy research at Strategas. The Nasdaq raced to a new closing high Monday as Apple and Amazon both reached records. The Russell 2000 also hit a new high.

Trade issues could creep into the market psyche later in the week. The tariffs on Canada and Mexico have made discussions around NAFTA more difficult, and now expectations for a revised North American Free Trade Agreement are fading.

Clifton said a NAFTA agreement needs to be struck in the next few days, in order for it to be approved by the current U.S. Congress, and there is also a Mexican election on July 1. As the deadline draws near, there could be more discussion of Trump withdrawing from the current NAFTA agreement.

The Trump administration is seen to be using tariffs and threats as negotiating tools, but there is concern that countries that have long been U.S. allies may take affront to the measures and the situation could escalate.

Canada's Prime Minister Justin Trudeau said the fact that the U.S. used national security concerns as a reason for the tariffs was "insulting." Trudeau also said Canada could not make a deal while the U.S. demands a sunset clause on NAFTA, making it basically a temporary arrangement.

G-7 could be unusual in that leaders may all openly oppose the U.S. president's actions. G-7 finance officials, meeting over the weekend, released an unusual statement asking Treasury Secretary Steven Mnuchin to express their "unanimous concern and disappointment" about tariffs to Trump.

"All signals point to fellow leaders making strong face-to-face rebukes of Trump (if for nothing else than domestic political considerations) that have the potential to create diplomatic tire fires," wrote Chris Krueger, political strategist at Cowen.

"Add in the near-collapse of the NAFTA negotiations and a new war of words between the North American allies, and we would expect some less-than-positive visuals out of Quebec as the awkward meter has to be near an eleven going into the Summit," he wrote.

Jack Ablin, CIO of Cresset Wealth Management, said investors are not overly concerned by the trade issues so far, even though stocks sold off when the latest tariffs were announced last week. "I just think it's bluster. I think most investors think it's a non-event. I think it's pretty much presidential arm-flapping. At the end of the day, he eventually listens to the voice of reason," Ablin said.