Updated

Sen. Charles Grassley stands by his "tweet."

The Iowa Republican, who last week used Twitter to criticize President Obama for telling Congress that it's "time to deliver" on health care reform, said Sunday that blasting out the taunt via short-hand text message was in no way beneath the office of senator.

He told "FOX News Sunday" Obama took a "cheap shot" at Congress, and that his response was "very senatorial."

"We've had a dialogue with this president since January the 20th on a program to get a bill to the floor ... for July and we're still on that timetable, and (for) the president to say that we ought to deliver it made it look like Congress wasn't working -- the very weekend that we were working Saturday and Sunday in Washington to keep on schedule while he was sightseeing," Grassley said.

"He didn't need to say that, it didn't contribute to it, it was a cheap shot."

Grassley, the top Republican on the Senate Finance Committee, was referring to Obama's "sightseeing" in Paris on the tail end of his trip to the Middle East and Europe.

He offered similar criticism on Twitter after Obama used his weekly radio address last Saturday to pose the health care challenge to Congress.

In his first tweet, Grassley wrote: "Pres Obama you got nerve while u sightseeing in Paris to tell us 'time to deliver' on health care. We still on skedul/even workinWKEND."

Then he wrote: "Pres Obama while u sightseeing in Paris u said 'time to delivr on healthcare' When you are a 'hammer' u think evrything is NAIL I'm no NAIL."