Vice President Pence observes as President Trump signs an executive order Dec. 6 formally recognizing Jerusalem as the capital of Israel. (Jabin Botsford/The Washington Post)

Vice President Pence delayed his trip to the Middle East and Germany this weekend and will remaining in Washington for a few extra days in case he is needed to cast a tiebreaking vote on Republican tax legislation, his spokeswoman said Thursday.

Pence was originally scheduled to depart late Saturday for a trip to Egypt, Israel and Germany. He now plans to leave Tuesday, arriving in Egypt on Wednesday for a bilateral meeting with Egyptian President Abdel Fatah al-Sissi. 

Republicans hold a narrow majority in the Senate and are desperate to push through their tax plan — which, if successful, would mark President Trump's only major legislative achievement this year — before the holiday break.

On Wednesday, Sen. John McCain (R-Ariz.), who is battling brain cancer, was hospitalized for side effects of his treatment, making the Republicans' already razor-thin margin even more precarious. The vice president can cast a deciding vote in the case of a tie in the Senate, and Pence has already done so several times this year. 

Alyssa Farah, Pence's press secretary, said in a statement Thursday that Republicans were so close to passing their tax legislation and the vice president decided to remain in Washington as a precaution. 

"Yesterday the White House informed Senate Leadership that due to the historic nature of the vote in the Senate on tax cuts for millions of Americans, the Vice President would stay to preside over the vote." Farah said. "The Vice President will then travel to Egypt and Israel, where he'll reaffirm the United States' commitment to its allies in the Middle East and to working cooperatively to defeat radicalism."

She added that Pence "looks forward to having constructive conversations with both Prime Minister Netanyahu and President [al-Sissi] to reaffirm President Trump's commitment to our partners in the region and to its future."

On Saturday, Palestinian President Mahmoud Abbas announced he would not meet with Pence on his trip to the Middle East, in response to Trump's decision earlier this month to recognize Jerusalem as the capital of Israel.

That decision — which also included eventually moving the U.S. Embassy there — also sparked widespread opposition among Christians in the Middle East and complicated another aspect of Pence's trip. The pope of the Egyptian Coptic church, who leads the largest Christian denomination in the Middle East, also canceled his planned meeting in Cairo with the vice president.

Though the White House had originally said part of the trip was intended to check in on Middle East Christians, Pence is now no longer scheduled to meet with a Middle East Christian representative. His stop in the West Bank city of Bethlehem, where he was to visit the Church of the Nativity, has also been canceled.

Pence was initially scheduled to visit Israel first but flipped the order of his trip to make Cairo his first stop. The change was made, an administration official said, because in the wake of the Jerusalem decision, the vice president felt it was important to address the entire Muslim and Arab world — and Egypt was a natural venue.

World and domestic events have intruded upon Pence's travel's before. In April, North Korea attempted a missile launch while the vice president was en route to Asia for a 10-day trip through the region. Pence called the failed launch a "provocation" when he arrived in Seoul the next day. He visited the demilitarized zone between North and South Korea during his trip.

In July, the vice president arrived in Tallinn, Estonia, for a 3½ -day trip intended to reassure the United States' Baltic allies of the administration's commitment to their security and NATO on the eve of Trump's expected signing of broad sanctions against Russia. And a month later, Pence's planned visit to South America coincided with turmoil in Venezuela after Venezuelan President Nicolás Maduro's autocratic government seized power and cracked down on dissent. 

At the time, Trump had alarmed countries in the region by threatening military action, and Pence found himself trying to smooth over the president's remarks, saying the administration's preference was for "a peaceable solution." 

His trip also came in the wake of a violent confrontation at a white-supremacist rally in Charlottesville that left one woman dead and sparked a national controversy and discussion about race after Trump said "both sides" were to blame.

Nearly 2,000 miles from Washington, in Cartagena, Colombia, Pence was forced to respond to his boss's latest controversy, again thrusting him into the role of Trump's global translator.

Loveday Morris in Jerusalem contributed to this report.