Sen. John McCain will return to the U.S. Senate Tuesday, according to a statement from his office.

"Senator McCain looks forward to returning to the United States Senate tomorrow," the statement read, "to continue working on important legislation, including health care reform, the National Defense Authorization Act, and new sanctions on Russia, Iran and North Korea."

McCain announced last week that he had been diagnosed with a glioblastoma, which is a type of cancerous brain tumor.

The tumor was discovered during surgery to remove a blood clot on his brain a week and a half ago.

Republicans in the Senate are expected to vote to repeal the Affordable Care Act soon, and McCain's vote could be crucial.