(Reuters) - Finance Minister Arun Jaitley may have to cancel a trip to the United States in October after he was moved to an isolation ward of a government-run hospital to recover from an infection that followed a stomach operation to treat diabetes.

Jaitley is due to attend a World Bank meeting on Oct. 10-12 in Washington, where he is also expected to meet senior government officials. He was due to leave on Oct. 8.

"It seems doubtful that he would be able to take the stress for the long journey to the U.S. and participate in the World Bank meeting," said a senior finance ministry official, adding the final decision would be taken in consultation with his doctors.

The 61-year-old lawyer, who also holds the defense portfolio in Prime Minister Narendra Modi's four-month-old government, had to skip a meeting of finance ministers from the Group of 20 nations in Australia this month.

Jaitley had been expected to visit the Pentagon during his trip to Washington.

He was admitted to a private hospital in New Delhi on Sept. 1 for gastric bypass surgery to treat weight gain he has suffered because of a long-standing diabetic condition. He was re-admitted to hospital last week, a doctor who operated on him said.

Jaitley, who had heart surgery several years ago, was moved to the isolation ward in a government hospital on Sunday to reduce the number of people visiting him after he contracted an infection, doctor Pradeep Chowbey told Reuters.

"He has been lodged in the AIIMS hospital to ensure control over people visiting him - a reason for him getting the infection," said Chowbey, referring to the All India Institute of Medical Sciences.

Jaitley is currently stable and is being monitored by a team of doctors at AIIMS, including those specializing in pulmonary medicine and cardiology, said hospital spokesman Amit Gupta.

Jaitley suffered some post-surgery complications at the previous hospital and his family wanted him to be shifted to AIIMS, Gupta added, saying he expected the minister to remain in the hospital for "a couple of days".

"No other surgery is expected as of now, he's stable, he is recovering from a chest infection," Gupta said.

A medical source said Jaitley's weak immune system was affected after he ate at a state dinner hosted during a visit to India by Chinese president Xi Jinping.

"He should have avoided that food, which was cooked hours before it was served. He needs to strictly follow the regimen and take proper rest for next few days," the source said.

Officials said Jaitley's absence from two key ministries for almost a month had begun to slow decision-making, including delays to appointments of officials such as the chief economic adviser in the finance ministry.

"We need a full-time minister to lead the ministry," said the finance ministry official, adding the government still had to start raising more than 584 billion rupees ($9.51 billion) through the sale of government stakes in state-run and private companies.

He said the minister's absence was also affecting work on a new goods and services tax, a key part of the minister's agenda.