WASHINGTON (Reuters) - The Senate could vote this week on Republican proposals that will ensure some government payments continue uninterrupted if Congress fails to approve increased federal borrowing authority, congressional aides said on Monday.

The federal government could bump up against its $14.3 trillion limit on U.S. debt sometime in April or May, requiring Congress to approve a higher limit so the Treasury could issue more debt -- or risk default.

The Obama administration wants prompt action by Congress to raise the government's borrowing authority to an unspecified new limit. But some conservative Republicans are balking at increasing borrowing authority until serious steps are taken to reduce spending.

Republican senators are planning to offer amendments to an unrelated patent reform bill being debated this week in the Senate. Those amendments would require Treasury to keep making debt payments -- many of them to Chinese and other foreign holders of U.S. debt -- as well as ensuring that senior citizens continue receiving Social Security benefits.

But under the plan, many other government activities would have to immediately halt.

Senator David Vitter said the amendments "would blunt some of this false sense of urgency" to raise borrowing authority -- "by ensuring we don't default on our most pressing obligations."

(Reporting by Richard Cowan, editing by Philip Barbara)