BEIJING — Secretary of State Rex W. Tillerson is scheduled to arrive in Beijing early Saturday for a brief visit, amid confusing signals about President Trump’s position on two questions looming over the confrontation with North Korea: Is America’s long-term goal to overthrow its leader, Kim Jong-un, or just try to change his behavior? And what would it take to get negotiations with Pyongyang started?

Mr. Tillerson, who is confronting a problem for which his background as chief executive of Exxon Mobil is of little help, has tried to reassure North Korea with his oft-repeated assertion that “we do not seek the collapse of the regime.” But Mr. Kim, and the Chinese, appear to be trying to square those calming words with President Trump’s tweets, including the ominous-sounding one he issued last weekend, warning that if the North’s foreign minister echoes the thinking of “Little Rocket Man, they won’t be around much longer.”

Similarly, Chinese officials are likely to scrutinize Mr. Tillerson to see if he is willing — or able — to provide clarity about the contradictory statements issued by top national security officials over the conditions under which American officials would actually talk with the North Koreans. Mr. Tillerson himself has been inconsistent, insisting months ago that Mr. Kim must first give up all his weapons, then arguing in August that he must simply pause their nuclear and missile testing.

But last week Mr. Trump’s national security adviser, H. R. McMaster, insisted that the North would have to agree to highly intrusive inspections to determine the whereabouts of its nuclear weapons, and agree to ultimately plan to surrender its arsenal. The North has never allowed inspectors far beyond its Yongbyon reactor facility, and its arsenal is now enshrined in its Constitution as something no official could ever trade away.