WASHINGTON — Bowing to pressure, President Barack Obama today announced changes to his health care law that would give insurance companies the option to keep offering consumers plans that would otherwise be canceled.

The administrative changes are good for just one year, though senior administration officials said they could be extended if problems with the law persist. Obama announced the changes at the White House.

Obama has been under enormous pressure from congressional Democrats to give ground on the cancellation issue under the health care overhaul, a program likely to be at the center of next year’s midterm elections for control of the House and Senate.

It’s unclear what the impact of the changes will be for the millions of people who have already had their plans canceled. While officials said insurance companies will now be able to offer those people the option to renew their old plans, companies are not required to take that step.

Insurance companies will be required to tell consumers who want to keep canceled plans about the protections that are not included under those plans. Customers will also be notified that new options are available offering more coverage and in some cases, tax credits to cover higher premiums.

Under Obama’s plan, insurance companies would not be allowed to sell coverage deemed subpar under the law to new customers, marking a difference with legislation that House Republicans intend to put to a vote on Friday.

Republicans were unimpressed with the changes.

House Speaker John Boehner, speaking in advance of the president’s announcement, insisted it was time to “scrap this law once and for all.”

“You can’t fix this government-run health care plan called Obamacare . ... It’s just not fix-able.”