During his first visit, in April, Rumsfeld offered his backing to Kyrgyzstan's new leadership. He also received assurances from the new leaders that U.S. forces would be able to continue using the Ganci air base to support U.S. operations in Afghanistan.
This second visit comes amid concern that the newly elected president, Kurmanbek Bakiev, may ask the United States to withdraw its troops from Kyrgyz soil.
Earlier this month, the Shanghai Cooperation Organization -- a regional grouping that includes Kyrgyzstan, Russia, China, Kazakhstan, Tajikistan and Uzbekistan -- said Washington should set a clear date for withdrawing from military bases in Central Asia.
Bakiev, speaking to journalists in Bishkek on 23 July, said Rumsfeld's visit would not be limited to a discussion of the U.S. military presence in Kyrgyzstan.
"We have bilateral relations with the U.S., not only in the military field, but also we have developed economic ties during the past several years. That is why, certainly, we will discuss economic relations issues during [Rumsfeld's] visit, and we will also discuss security issues," Bakiev said.
The U.S. first deployed troops in the country in the wake of the 11 September 2001 terrorist attacks. The Ganci base is currently home to around 1,000 U.S. military personnel.
Speaking ahead of Rumsfeld's arrival, Kyrgyz Foreign Minister Roza Otunbayeva said the issue of the American military presence in Kyrgyzstan would be raised, saying it's the main reason for Rumsfeld's visit.
Michael Hall, the director in Bishkek of the International Crisis Group's Central Asia Project, tells RFE/RL that Rumsfeld's visit appears to have come at relatively short notice.
"It certainly does look as it was rather sudden and it's probably an attempt by the United States to ensure that it's got a continuing relationship, continuing military partnership with the new Kyrgyz government. So, I think it's quite possible, yes, this is a reaction to some of the statements that have followed the Shanghai meeting," Hall said.
Some observers like Mark N. Katz, a professor of government at U.S.-based George Mason University, suggest that the Bakiev administration's numerous and sometimes contradictory statements are merely attempts to get more money from the United States to operate the base.
Katz was quoted by Russia's RIA-Novosti today.
Russia's "Vremya Novostei" daily wrote today that the Pentagon chief may announce Washington's intention to allocate grants as well as give up to $200 million in no-interest loans to the new Kyrgyz government in exchange for using its soil for military operations. This couldn't be independently confirmed.
So, is it an attempt to "buy" the Bakiyev government's favor?
"I think there is a great deal of concern in the international community about more instability in Uzbekistan, for example. And in order for this not to affect the region as a whole, there needs to be the support of neighboring states," Hall said. "So, there may be a certain degree of wanting to, as you put it, 'buy' some favor with the Kyrgyz government. But it may be a part of a genuine effort as well to increase stability in the region at a time when stability in a region as a whole is in serious danger."
Last week, the U.S. Senate approved $35 million for democratic projects in Kyrgyzstan.