WASHINGTON (Reuters) – U.S. Vice President Mike Pence will delay an upcoming Middle East trip by a few days in case a tie-breaking vote is needed from him for tax cut legislation in Congress, a senior White House official said on Thursday.

Pence will now leave some time on Tuesday on a trip that will begin with a visit to Cairo for talks with Egyptian President Abdel Fattah al-Sisi, the official said.

He had initially planned to leave late on Saturday.

As vice president, Pence can cast a tie-breaking vote in the U.S. Senate, and with a close vote expected along party lines on the tax legislation, it was decided to keep him in the country just in case. Republican Senator John McCain, who is fighting brain cancer, was in hospital on Wednesday.