Less than two months before being sworn into office, President-elect Donald Trump has yet to sign the presidential transition paperwork that unlocks critical clearances, information and access to White House resources for his transition team.

Political experts say this is worrisome because history shows the period early in a presidency can be a vulnerable time for a new administration, and the point of easing the transition is so a new president’s staff can access government offices early and avoid problems.

Trump, who has rapidly announced senior staff and Cabinet picks over the last 15 days, has still not finalized multiple agreements that are foundational for his team to begin receiving confidential information and briefings across all federal agencies, as well as millions of dollars in transition resources, including office space and staff assistance.