President Donald Trump signed his first executive order on Friday, heading into the Oval Office shortly after his inaugural parade to direct agencies to ease regulations associated with Obamacare, the signature healthcare law of his predecessor that Trump has vowed to replace.

The White House also directed an immediate regulatory freeze for all government agencies in a memo from Trump's chief of staff, Reince Priebus, White House spokesman Sean Spicer said.

The White House did not immediately provide details about what the executive order or memo entailed.

Repealing and replacing the Affordable Care Act was a central pledge for Trump during the presidential election campaign, although Republicans in the U.S. Congress have not yet laid out a plan to replace the insurance program.

In a hastily arranged signing ceremony, with some of his top aides around him, Trump sat behind the presidential Resolute Desk, signing the order. He also signed commissions for his newly confirmed Defense Secretary James Mattis and his Homeland Security Secretary John Kelly.

Trump spoke briefly about his day with reporters. "It was busy, but good. It was a beautiful day," Trump said.

Vice President Mike Pence then swore in Mattis and Kelly in a separate ceremony.

There were other signs of change in the Oval Office, which former President Barack Obama vacated on Friday morning. Golden drapes hung where crimson ones had earlier in the day, and new furniture dotted the room.