WASHINGTON — A bipartisan slate of U.S. senators will present a resolution calling on the Obama administration to make a “nuclear-weapons capability” by Iran a red line.

The non-binding resolution, to be introduced Thursday by Sens. Robert Casey (D-Pa.), Joe Lieberman (I-Conn.) and Lindsey Graham (R-S.C.) “urges the President to reaffirm the unacceptability of an Iran with nuclear-weapons capability and to oppose any policy that would rely on containment as an option in response to the Iranian nuclear threat.”

Israel and the United States have differed since the last Bush administration over what should trigger a military strike: Iran’s acquisition of a nuclear weapon, which has been the American red line, or the capability to build and deliver such a weapon, which has been the Israeli red line.

However, in recent months there have been signs that the Obama administration is drawing closer to how Israel sees the point of no return.

In a little noticed joint statement issued in December after a session of the U.S.-Israel security dialogue, William Burns, the deputy U.S. secretary of state and his Israeli counterpart, Daniel Ayalon, said that “continued efforts by the international community are critical to bringing about change in Iranian behavior and preventing Iran from developing a nuclear weapons capability.”

Israeli officials at the time welcomed as significant the use of the word “developing” as opposed to “acquiring.”

Within weeks, Leon Panetta, the defense secretary, also was using the term. “Our red line to Iran is to not develop a nuclear weapon,” he told CBS on Jan. 8. “That’s a red line for us.”

Ehud Barak, the Israeli defense minister, has said that Iran could achieve capability before the end of this year.