WASHINGTON (Reuters) - U.S. House Speaker Mike Johnson defended a stopgap measure aimed at funding the federal government through mid-March and averting a partial government shutdown despite complaints from some fellow Republicans and Donald Trump ally Elon Musk.

Johnson, in an interview on Fox News, said the bill was necessary to keep the government operating until U.S. President-elect Trump and his fellow Republicans had full control of Congress and could fully enact promised bigger spending changes.

Tesla founder Musk, who along with fellow businessman Vivek Ramaswamy were tasked by Trump to lead an outside advisory panel that they say will make the government more efficient, balked at the spending bill and urged lawmakers to reject it.

"This bill should not pass," Musk wrote in an early morning post on X.

Johnson told Fox that he had spoken with Musk and Ramaswamy about the bill's circumstances Tuesday night, including the 219-211 majority Republicans hold in the chamber while Democrats still control the Senate and White House until next month.

"Elon and Vivek and I are on a text chain together, and I was explaining to them the background of this," he said. "They understand the situation."

Other Republican lawmakers voiced opposition to the bill, which must pass by Friday night in order to prevent a partial shutdown that would start on Saturday unless Congress acts.

The tentative deal would likely keep the roughly $6.2 trillion federal budget at its current level, and includes $100.4 billion in fresh disaster aid as well as $10 billion in economic aid for farmers.