WASHINGTON - US Senator Chuck Schumer said on Tuesday that he had decided to support Chuck Hagel's nomination as defense secretary, providing a critical boost to the former Republican senator's chances of being confirmed by the Senate.Schumer, a key Democrat from New York state, said his concerns over Hagel's positions on Israel, Iran and other issues were addressed after they met with for about 90 minutes on Monday. He described Hagel as "forthcoming and sincere.""Based on several key assurances provided by Senator Hagel, I am currently prepared to vote for his confirmation," Schumer said. "I encourage my Senate colleagues who have shared my previous concerns to also support him."A Vietnam veteran who split from fellow Republicans by opposing the US-led war against Iraq, Hagel was nominated by President Barack Obama on January 7 to replace outgoing Defense Secretary Leon Panetta.Hagel has spent much of the past week calling and writing senators whose votes could be crucial for his confirmation.Critics have sought to portray Hagel as anti-Israel and as someone who is not committed to preventing Iran from obtaining a nuclear weapon, accusations the former Nebraska politician strongly denies.Former US Secretary of State Colin Powell, a fellow Republican, strongly endorsed Hagel over the weekend as someone who "will fight a war if it's necessary, but he is a guy who will do it with great deliberation and care."Schumer's decision bolsters the likelihood Hagel will win his confirmation battle. Democratic Senator Barbara Boxer of California was due to speak shortly after Hagel wrote her a letter addressing her concerns about his nomination.