Grant PR a binding referendum, subject to the vote of Congress. Off early multiple options of statehood, status quo, and Independence. Statehood would require an overall majority vote for the measure to pass (independence as well theoretically, but they won't get more than around 5% of the vote).
They already have a two-option Y/N statehood vote in November, so if Yes wins, that's all Congress needs to admit them. In fact, it would be a really bad look on the world stage if we have a part of our country not represented in Congress that wants to be, and have it denied for political reasons.