Nelson criticized House Republicans for threatening a government shutdown unless ObamaCare is defunded, but he also said that if the federal debt ceiling is not raised by mid-October that it would undermine critical foreign policy negotiations.

Nelson pointed to negotiations between the United States and Russia to eliminate Syrian chemical weapons stockpiles, new leadership in Iran, and a possible two-state deal between Israel and Palestine as reasons why Republicans should not be putting political conditions on raising the debt ceiling.

“We suddenly have in the international arena, a bunch of new things that might be optimistic signs,” Nelson said. “Would we want to weaken the United States government as it negotiates over these critical matters?”

House Republicans are expected to release a measure to raise the debt ceiling later this week. The plan will include a one-year delay of ObamaCare implementation and approval of the Keystone XL pipeline, among other GOP priorities. President Obama and congressional Democrats have called for a "clean" raise on the debt ceiling.