The White House is confident its discussions with Rep. Joe Sestak (D-Pa.) were "not problematic," Press Secretary Robert Gibbs said Tuesday.

Gibbs said that the White House believes its conversations with Sestak about his primary challenge against Sen. Arlen Specter (D-Pa.) did not cross any lines, amidst claims by Sestak that he was offered an administration job in exchange for dropping his campaign.

"I'm told that whatever conversations have been had are not problematic," Gibbs said during his daily briefing with reporters.

Rep. Darrell Issa (R-Calif.), the top Republican member of the House Oversight and Government Reform Committee, has been pressing the White House and Gibbs for answers on the discussions between the administration and Sestak.

President Barack Obama had quickly endorsed Specter's reelection campaign after the former Republican senator switched parties, giving Democrats a decisive 60-vote majority that had lasted for some months. The job offer Sestak alleges would have been meant to clear the primary field for Specter.

Issa suggested the administration had been handling his questions in a "Nixonian" manner.

"I think Congressman Sestak has discussed that whatever has happened is in the past and he's focused on his election," Gibbs said Tuesday.