WASHINGTON — In defiance of federal law, the State Department is refusing to submit reports to Congress detailing efforts by Saudi Arabia and the United Arab Emirates to alleviate the humanitarian crisis in Yemen, according to legislators and congressional aides.

Trump administration officials have missed both congressionally mandated deadlines this year to submit the biannual reports, most recently last week. This has further inflamed tensions between the administration and legislators who were already furious with the administration’s unflagging support of the Saudi government and were still stung by the White House’s decision in May to circumvent Congress to sell arms to Riyadh.

“Congress has tried again and again to bring accountability and transparency to America’s role in the war in Yemen. At every turn, the Trump administration has blocked our efforts,” said Representative Eliot L. Engel, Democrat of New York and the chairman of the Foreign Affairs Committee. “But we won’t stop looking for ways to dial back our involvement in a conflict that’s fueling the world’s worst humanitarian crisis.”

Last year, Senator Todd Young, Republican of Indiana, and Senator Jeanne Shaheen, Democrat of New Hampshire, both of whom sit on the Foreign Relations Committee, successfully added a provision to the military defense policy bill that required the State Department to submit certifications to Congress describing the actions Saudi and Emirati officials have taken to reduce the risk of harm to civilians.