Peretz's schedule for his trip was finalized only in recent days after officials close to the defense minister said he "encountered difficulty" in getting the meetings he wanted.
In comparison, Mofaz consistently met with the secretary of state on his visits to the US. Mofaz most recently visited the US as transportation minister and met with Rice.
"It is unheard-of that an Israeli defense minister goes to the US and doesn't meet with the secretary of state or the vice president," said a senior Israeli diplomat who is familiar with procedures in Washington. "The only conclusion is that the Americans do not take him seriously."