DUBAI, United Arab Emirates — The U.S. continues to push for an end of the four-nation boycott of Qatar, even after the hospitalization of Kuwait's ruling emir who led talks to resolve the yearslong dispute, a U.S. diplomat said Sunday.

U.S. Special Representative for Iran Brian Hook acknowledged the challenge ahead on ending the crisis that's torn apart the Gulf Cooperation Council, with Bahrain, Saudi Arabia and the United Arab Emirates part of the boycott that's targeted fellow member Qatar since June 2017. Egypt as well joined the boycott, which saw nations close their airspace and borders to Qatar.

Kuwait and Oman, the two other nations in the GCC, have sought dialogue between the nations since, with Kuwait's emir Sheikh Sabah Al Ahmad Al Sabah leading those efforts.

Sheikh Sabah was hospitalized in Kuwait City on July 18, underwent surgery the next day and later traveled via a U.S. Air Force C-17 flying hospital to Rochester, Minnesota, home of the flagship campus of the Mayo Clinic. Kuwait has yet to say what ails the 91-year-old ruler.

"My expectation is that the role that Kuwait has been playing will continue," Hook told journalists on a conference call after meeting Qatari officials in Doha. "The emir is at the Mayo Clinic. As I said, the United States very much hopes and prays for his improved health."

Hook said he planned to travel Monday to Kuwait City to meet with officials there.

"I've seen some steps backward over the last couple of years," Hook said. "We've reached points where I think both sides were optimistic and we've reached points where both sides were pessimistic.

"I think our role and the role of Kuwait is to do what we can to foster dialogue, to help them make progress."

The four countries cut ties to Qatar on June 5, 2017, just after a summit in Saudi Arabia in which Gulf leaders met with President Donald Trump. They say the crisis stems from Qatar's support for extremist groups in the region, charges denied by Doha.

The four nations have also pointed to Qatar's close relationship with Iran, with which it shares a massive offshore gas field that provides the peninsular nation its wealth. Qatar restored full diplomatic ties to Iran amid the dispute.

Hook, who is leading U.S. efforts to extend an arms embargo on Iran, said the topic came up during his talks Sunday with Qatari Foreign Minister Sheikh Mohammed bin Abdulrahman Al Thani.