WASHINGTON — In a boon for the Obama administration’s efforts to advance the nomination of Chuck Hagel as secretary of defense, Senator Charles E. Schumer of New York told President Obama on Tuesday that he was optimistic that he could vote for Mr. Hagel’s confirmation based on his grilling of Mr. Hagel on a variety of issues pertaining to Israel and Iran.

After a 90-minute meeting in the West Wing of the White House on Monday, Mr. Schumer appeared to be mollified on a number of concerns he has with some votes Mr. Hagel made while serving in the Senate and myriad comments he has subsequently made regarding the nuclear threat of Iran and other matters.

“Based on several key assurances provided by Senator Hagel,” Mr. Schumer said in a prepared statement, “I am currently prepared to vote for his confirmation. I encourage my Senate colleagues who have shared my previous concerns to also support him.” Mr. Schumer, the first senator to meet privately with Mr. Hagel since he was nominated last week, is likely to have influence over many of his Senate colleagues, particularly Democrats, who have been fretting over the nomination. He called Mr. Hagel Tuesday morning to let him know he was prepared to support him.

While the nod is unsurprising, having the support of Mr. Schumer, the most influential Jewish member of the Senate, may be helpful to Mr. Hagel’s pursuit of the defense job, effectively neutralizing the idea that he is somehow anti-Israel. His nomination has been met with suspicion, and even outright hostility, among Republicans and Democrats who are strongly aligned with pro-Israel groups.