A State Department official confirmed that Mr. Blinken will travel to both countries after the top US diplomat’s plane made a brief stopover in Ireland on Sunday en route to Saudi Arabia.
The trip was announced after US President Joe Biden discussed ongoing talks on a ceasefire in the Gaza Strip with the release of hostages during a telephone conversation with Israeli Prime Minister Benjamin Netanyahu on Sunday.
Egypt, Qatar and the United States have been trying to broker a new ceasefire between Israel and the Islamist militant group Hamas for months.
Mr. Biden also reiterated concerns that Israel could launch an operation in Rafah, the southern Gaza city where more than a million Palestinians have taken refuge.
The State Department did not immediately provide details on the two stops.
US State Department spokesman Matthew Miller said in a statement announcing the visit to Saudi Arabia that Mr. Blinken would push for a ceasefire, but added that “it is Hamas that stands between the Palestinians and a ceasefire.”