(CBS News) WASHINGTON, D.C. - Israeli Prime Minister Benjamin Netanyahu's visit to Washington next week comes at a delicate moment in U.S.-Israeli relations, as President Barack Obama and Netanyahu try to sort out what to do about Iran's developing nuclear program.
The Obama administration says there's still "time and space" to pursue diplomacy with Iran, but that may not be enough for the Israelis. Netanyahu plans to press Mr. Obama to state publicly and clearly that the U.S.'s so-called red line is to prevent Iran from gaining nuclear capability and not just a nuclear weapon.
The last time Mr. Obama and Netanyahu met, in May 2011, it did not go well, as the two leaders differed over potential borders for an independent Palestinian state. Now, with their next meeting dominated by concerns over Iran, tension is already building over whether the U.S. has done enough to prevent Iran from developing a nuclear weapon. The Israelis fear they would be a nuclear Iran's first target.
The White House faces skepticism not just from Israel, but also members of Congress. On Capitol Hill Wednesday, Secretary of Defense Leon Panetta tried to offer reassurance.
"We are committed not just to contain, but to prevent Iran from getting a nuclear weapon," Panetta told lawmakers.
Secretary of State Hillary Clinton also faced tough questions from some staunch supporters of Israel who question the administrations resolve. When asked by Rep. Gary Ackerman, D-N.Y., if there were any "red lines that the Iranians cannot cross," Clinton said that "it's probably smarter for us to be pressing on the sanctions and the negotiations."
But Netanyahu does not believe the sanctions have done enough and will press the president to do more. For his part, White House press secretary Jay Carney aid Mr. Obama would be "specific and direct" when the two meet next week.
Questioned over whether the U.S. would defend Israel in the event that Iran retaliates for a pre-emptive Israeli strike, Carney said "that's a couple of 'ifs' down the road. What I can say is we have an unshakeable commitment to Israel's security."
On Capitol Hill, a group of senators said Congress would support military action if it comes to it.
""The Iranian regime will not be allowed to possess nuclear capability, and if that means military action, so be it," Sen. Lindsey Graham, R-S.C., told reporters.
Israel is concerned that Iran is about to enter a "zone of immunity" where it would be difficult to take out their nuclear weapons program. Despite the fact that the Pentagon has a deep bunker-busting bond that could reach the program Iran has buried in the mountains, that's one of the concerns that will make for a very tense meeting.