Haiti’s security crisis is reaching a breaking point. An alliance of armed gangs is pressing the country’s prime minister to resign, placing the United States in the middle of a power struggle gripping the country. Aiming to ease the standoff, the Biden administration is increasing pressure on Prime Minister Ariel Henry to enable a transfer of power.

The United States was not actively “calling on him or pushing for him to resign,” Matthew Miller, a spokesman for the State Department, said. But, he added, “we are urging him to expedite the transition to an empowered and inclusive governance structure.”

The impasse points to a major inflection point in Haiti, which has been plagued by nearly perpetual crises over the last several years, as tempers flare in the country of 11.5 million people over spreading unrest, food shortages and a lack of progress in moving toward democratic elections and restoring a sense of security.

The standoff emerged after Mr. Henry, who has been backed by the United States since becoming Haiti’s de facto leader after the assassination in 2021 of President Jovenel Moïse, was unable to return to Haiti on Tuesday because of doubts over safely landing at the airport in the capital, Port-au-Prince, which has been targeted in recent days by gang assaults.

Mr. Henry, after landing instead in Puerto Rico on Tuesday, has not made any public statements about his whereabouts or plans to return to Haiti. In the meantime, as scenes of looting and disarray have many people in Port-au-Prince on edge, gang leaders have rushed to fill a power vacuum.