As Israeli Prime Minister Benjamin Netanyahu flew back after a UN speech during a visit to the United States, his key aides said Sunday that he succeeded in both pressing concerns over Iran's nuclear program and smoothing the oft-rocky relations with U.S. President Barack Obama's administration.

"The first thing that he succeeded in doing was sharpening the message on Iran," one of the aides told The Jerusalem Post.

"We were more specific about what we think should be the red lines, and that is important in framing the parameters of the debate," according to the aide, and Netanyahu has said that Iran could be ready to build a bomb within six months.

In an address before the UN General Assembly, Netanyahu utilized a sketch of a bomb and fuse and a red magic marker to emphasize his belief that little time remains for the West to halt Iran's nuclear program before it succeeds in achieving the ability to build a nuclear weapon.

The Israeli prime minister called to set for the Iranian nuclear issue a "red line" beyond which the military force -- whether by Israel alone or with the United States and other Western nations -- may be the only recourse.

"Nothing has changed in the Iranian nuclear program," Netanyahu told Israeli television, "Perhaps people did not know the pace of progress (of the Iranian program) and that is what my speech meant to present. Time is running out."

Speaking with Israeli media at the conclusion of his visit, Netanyahu said, "I think that placing a red line is the best guarantor to prevent the need for military action."

However, U.S. officials, including Obama, contended that there is still time before Iran reaches their own "red line" -- the actual construction of a nuclear device, and stressed the need to allow international sanctions and diplomatic pressure to coerce Teheran into stopping its nuclear fuel enrichment program.

During his visit, Netanyahu held a telephone conversation with Obama and met with Secretary of State Hillary Clinton, as well as Canadian Prime Minister Stephen Harper and other officials.

White House Spokesman Jay Carney said in a statement that Netanyahu and Obama held a "prolonged" discussion, and " underscored that they are in full agreement on the shared goal of preventing Iran from obtaining a nuclear weapon."

The Israeli prime minister's aide said Netanyahu's talks with U. S. officials "strengthened and enhanced our dialogue with the U.S. administration over these issues."