"In my view, there's a changed sense of willingness to at least be open to talking to one another and that was not the case before I came," Tillerson said, speaking on the plane to reporters after he left Doha, Qatar. "We tabled some documents with both sides while we were here which lays out some ways that we might move this forward."
But he added that some issues are going to be complex "so the final and ultimate resolution may take quite a while."
The top US diplomat spent the early part of the week shuttling between Turkey, Kuwait, Saudi Arabia and Qatar in an attempt to resolve a dispute that complicates the Trump administration's priority of defeating ISIS. All the countries are members of the anti-ISIS coalition and Qatar is home to the largest US military base in the Middle East.
"All four of these countries are really important to the US," Tillerson said. "We have relations with all four of them, they're really important to us from a national security standpoint."
For now, though, Tillerson noted that the parties "are not even talking to one another at any level." The objective is to get them to have face-to-face discussions of the issues, Tillerson said. "There's a long list of issues but we also provided some guidance on how they might think about dealing with those," he added.
The talks helped him understand how "emotional some of these issues are," said Tillerson, who said he has been talking to the sparring neighbors "every other day" since the diplomatic stand-off began June 5.
Saudi Arabia, Bahrain, the United Arab Emirates and Egypt have cut diplomatic ties with Qatar, accusing it of supporting terrorism. They have closed their airspace to Qatar's airline. They also banned their citizens from traveling to or residing in Qatar after giving Qatari citizens 14 days to leave their countries after the decision was announced June 5.
The dispute reflects long-standing Gulf frustration with Qatar's foreign policy, including its support for Islamist groups and its ties to Iran, with which Qatar shares the world's largest gas field.
Gulf officials have said the restrictions will stay in place until Qatar meets a series of demands, including severing all ties with Iran and "terrorist" groups, shutting down the Qatari media organization Al Jazeera, ending its military cooperation with Turkey and halting the construction of a Turkish military base on its territory, and aligning its foreign, military and political policies with its neighbors. Qatar has rejected those demands.
Tillerson said part of his approach was to try to break down the areas of disagreement into "buckets, if you will, where I think they're easier to deal with."
"In terms of some of the things that are in those categories," Tillerson said, "I do think can be addressed up front fairly quickly, some of them are going to be I think more complex, are going to take longer."
During his trip, Tillerson signed a memorandum of understanding between the US and Qatar on fighting terrorism, saying he hoped it might help facilitate progress on the dispute.
However, the other four states responded with a joint statement saying the announcement of the memorandum was "not enough," and that sanctions on Qatar would continue until the "just and full demands that will ensure that terrorism is addressed and stability and security are established in the region."
The statement thanked the US for its "efforts" in the "fight against terrorism and its financing," saying the memorandum was the result of "repeated pressures and demands" from the four nations for Qatar "to stop its support for terrorism." Qatar denies that it funds or supports extremist groups.