It will be very challenging for the U.S. and China to come to an agreement about trade this week, in part because the Trump administration has been "unclear in what it really wants," a strategist said on Friday.

"On the one hand, the President remains very focused on the size of the bilateral trade deficit, and reportedly the Chinese has come to Washington with a package of about $200 billion worth of purchases that would certainly remedy a large portion of that deficit," said Amy Celico, principal at the Albright Stonebridge Group, a global strategy and business advisory firm.

But on the other hand, the U.S. administration and Congress want China to change some of its behavior on unfair trade practices, and seek to put an end to subsidies for advanced technology industries and forced technology transfers.

However, those would be challenging for China to make concessions on as it deems them to be "core interests" that it will not give up for a quick trade deal with Washington, Celico told CNBC's "The Rundown."

Celico's comments follow President Donald Trump's meeting with the leader of the Chinese trade delegation, Vice Premier Liu He on Thursday, as the two economic powerhouses kick off a second round of negotiations.

The White House described the meetings as part of "ongoing trade discussions" and said: "The United States officials conveyed the President's clear goal for a fair trading relationship with China."

Earlier on Thursday, Trump criticized China and other trading partners as being "very spoiled" on trade with the U.S., but said he was aiming for an overall deal with Beijing.

Speaking to reporters at the White House, Trump said China had "ripped off" the United States for too long and that he told Chinese President Xi Jinping that "we just can't do that anymore."

Trump was "trying to act a bit tougher after he seemed to be making quite a significant concession to the Chinese in renegotiating the remedy for ZTE's non-compliance with the package that was put in place after it was found to have broken American sanctions laws," said Celico, on the president's comments.

— Reuters contributed to this story.