Another Democratic challenger to Sen. Kirsten GillibrandKirsten GillibrandSenate Democrats: ObamaCare repeal fight isn't over yet Bipartisan senators seek to boost expertise in military justice system Mattis gaining power in Trump’s Cabinet MORE (D-N.Y.) dropped out of the race on Tuesday, further clearing the field for the new senator as she heads into her first reelection bid.

In a statement, Manhattan Borough President Scott Stringer, who had formed an exploratory committee, said he will focus on his reelection campaign instead of pursuing the Senate.

Stringer's announcement comes four days after Rep. Steve Israel (D-N.Y.) also announced that he won't run against Gillibrand.

Israel noted that President Barack ObamaBarack ObamaAppeals court overturns decision requiring EPA coal jobs report Obama ethics czar: Trump fundraiser at his DC hotel ‘illegal’ Trump greeted by protesters at campaign fundraiser MORE urged him to clear the Democratic primary for Gillibrand, something Stringer also noted in his statement.

"In light of President Obama's clear desire to avoid a Democratic primary in New York state, I have decided to focus on my re-election race for Manhattan Borough President and to suspend my exploratory committee and fund-raising efforts for the 2010 Senate race," Stringer said.

The Hill reported Tuesday that Obama and, in particular, Sen. Charles SchumerCharles SchumerTrump taps Dem Senate aide for energy commission Tougher Russia sanctions bill facing another setback Trump claims GOP has a 'big surprise' on healthcare MORE (D-N.Y.) have gone on the offensive to try to prevent a messy Democratic Senate primary next year.

Other New York Democratic representatives are looking at the race. Congresswoman Carolyn Maloney (D-N.Y.), in particular, is reportedly telling people that she will run.

Rep. Carolyn McCarthyCarolyn McCarthyWhy Congress needs an openly atheist member, now Lobbying World Lobbying world MORE (D-N.Y.) has also indicated she is considering at the race.

jeremy.jacobs@thehill.com