ABC News' Teddy Davis reports:
Sen. John McCain, R-Ariz., is stepping up pressure on President Obama to go forward with a planned troop build-up in Afghanistan despite rising opposition to the move from some members of the president's own party.
"I have some sympathy for the president but I think the president was right during the campaign and I think he was right in March when he said we have to prevent Afghanistan from becoming a terrorist haven," said McCain.
McCain stepped up pressure on his 2008 rival while participating in a conversation with Rober Kagan which was sponsored by the conservative Foreign Policy Initiative at the W Hotel in Washington, D.C.
McCain's remarks came one day after the Washington Post reported that Gen. McChrystal has sent Defense Secretary Robert Gates a confidential assessment which states that he needs more forces in Afghanistan within the next year and that without them, the eight-year conflict "will likely result in failure."
During his Tuesday foreign policy talk, McCain repeatedly said that he has "sympathy" for his 2008 rival because opposition to "further engagement in Afghanistan" runs high on the Left, which McCain characterized as President Obama's political base.
"I have some sympathy . . . But it's a tough job," said McCain. "Throughout history leaders have gone against the majority of public opinion either in their party or in the country."
McCain portrayed the US challenge in Afghanistan as being similar to the US decision to pursue a "surge" strategy in Iraq.
"If you try to win a conflict on the cheap . . . then you most likely fail," said McCain.
McCain is not alone among high-profile Republicans pressuring Obama on Afghanistan.
In an interview with FORTUNE magazine which was released on Tuesday, former Bush Secretary of State Condoleezza Rice said: “The last time we left Afghanistan, and we abandoned Pakistan...that territory became the very territory on which Al Qaeda trained and attacked us on September 11th...It’s that simple. If you want another terrorist attack in the U.S., abandon Afghanistan.”
ABC News' Rick Klein contributed to this report.