Former U.S. Senate Majority Leader Bob Dole is shown on Capitol Hill in Washington, March 31, 2009. (Chip Somodevilla / Getty Images)

Former Senate Republican Leader and presidential nominee Bob Dole has been hospitalized at Walter Reed Army Medical Hospital, according to Senate Majority Leader Harry Reid.

Reid, D-Nev., told colleagues on the floor of the U.S. Senate Tuesday evening that Dole, 89 years old, called him a few days ago to tell him that he is at Walter Reed and that it is "not for a checkup."

"He is infirm, he is sick," Reid said of Dole, who has been hospitalized many times over the years. "We should do this to recognize what a great leader Bob Dole is," Reid said.

Sen. John McCain said that Dole also reached out to all senators with an email sent from the hospital Monday to specifically ask for them to support on the Convention of Persons with Disabilities (CRPD) legislation. The legislation, which addresses disability rights, is making its way through the Senate.

"I hope my colleagues would, before deciding to vote, at least listen to the letter that was addressed to all of us by Senator Bob Dole," McCain said reading parts of the Dole letter, "As you may know, tomorrow the senate will vote on CRPD. Unfortunately, I am currently at Walter Reed and so cannot call you personally but wanted to connect with you via e-mail and ask for your help. I hope you will support this important treaty."

Dole was the 1996 Republican presidential nominee and 1976 GOP vice-presidential nominee.