The British government-run National Health Service on Tuesday ordered every hospital in England to cancel all non-urgent surgeries in order to free up staff and beds for emergency patients.

The NHS order will result in around 50,000 operations being postponed until at least February as overcrowded hospitals struggle to tend to everyone, the Telegraph reported. A spike in winter flu has forced frail patients to face 12-hour waits while some hospital corridors are running out of space.

British Prime Minister Theresa May apologized on Thursday to the patients whose operations were canceled, calling the situation "frustrating."

"I know it's difficult, I know it's frustrating, I know it's disappointing for people and I apologize," May told Sky News during a visit to a hospital outside London.

The NHS order followed claims by senior doctors that patients were being treated in "third world conditions," as more people flood hospitals in England with colder-than-usual winter weather bringing more cases of the flu and related issues, including respiratory illnesses.

One London-based doctor said that he was practicing "battlefield medicine" because conditions were so bad.

By Tuesday night, 12 different NHS trusts, or branches, said they had reached the maximum state of emergency, including two ambulance services covering almost nine million people.

The NHS, which delivers free health care for all citizens in England, accounts for a third of government spending on public services, Reuters noted.

Some American politicians, such as former presidential candidate Sen. Bernie Sanders (I., Vt.), have pushed for a single-payer health care system like Britain's, claiming that such a system would cost less and cover all citizens.

Washington Examiner managing editor Philip Klein wrote in an op-ed published Wednesday that as liberal Americans look towards a single-payer system, they need to realize the trade-offs involved, including long waits times and surgery postponements.