ISLAMABAD, Pakistan — An inflammatory call by an American congressman for the secession of Pakistan’s largest province has sparked uproar in the country, injecting fresh complications into stalled efforts to restart diplomatic relations between Washington and Islamabad.

The furor stems from a nonbinding resolution introduced Friday by Representative Dana Rohrabacher, Republican of California, which stated that the people of Baluchistan, a sprawling western province racked by a seven-year-old separatist insurgency, should “have the right to self-determination and to their own sovereign country.”

Although the bill has little chance of success in Congress, it drew a furious reaction from Pakistani politicians and media, with Prime Minister Yousaf Raza Gilani calling it an attack on Pakistani sovereignty, while the new ambassador to Washington, Sherry Rehman, warned it would “seriously impact Pakistan-U.S. relations.”

Media reports here accused Mr. Rohrabacher of seeking to “balkanize” Pakistan, or of acting at the behest of American intelligence agents who, the reports said, are seeking to pressure Pakistan into establishing covert listening posts on the border with Iran. Mr. Rohrabacher and Obama administration officials rejected those accusations.