Hillary Clinton came out against a movement to economically isolate Israel through boycotts, sanctions and divestment in a letter to a top donor.

The letter, which was sent on Thursday but released on Monday, asked Haim Saban, an Egyptian Jewish donor who has raised millions of dollars for the Clintons, for advice on how to fight back against attempts to "isolate and delegitimize Israel."

"I know you agree that we need to make countering BDS a priority," she wrote, referring to the name of the campaign pressure and isolate the Jewish state.

Clinton argued that outside intervention is not the best way to achieve the two-state solution or peace between Israelis and Palestinians.

"This is not the path to peace. I remain convinced that Israel's long-term security and future as a Jewish state depends on having two states for two peoples," Clinton wrote. "But this outcome can only be achieved through direct negotiations between Israelis and Palestinians — it cannot be imposed from the outside or by unilateral actions."

Clinton went on to tout her record of consistently opposing anti-Israel resolutions at the United Nations' Human Rights Council, condemning the "biased" Goldstone Report on the conflict in Gaza and standing up for Israel's self-defense. She also wrote of her record of making sure the United States blocked Palestinian attempts at the U.N. to declare statehood.

Republican presidential candidates have made support for Israel and its security a hallmark of their foreign policy. In condemning the BDS movement, Clinton noted a rising tide of anti-Semitism in Europe.

"Time after time, no matter the venue, I have made it clear that America will always stand up for Israel — and that's what I'll always do as president," Clinton said.

Saban, who spent part of his life in Israel, has raised $1.9 million for the Clintons and donated over $2 million to pro-Clinton Priorities USA PAC. Some of the Left have been supportive of the BDS movement.