Of course.
Credit agencies don't just look at the debt ratio or the total amount of debt. They also look at the government's ability to pay interest on the debt, as well as the government's economic and fiscal outlook.
It will still receive a fairly good rating even with a large debt, if the economy is strong, the fiscal outlook is favourable, the government's production capacity is good, and it is able to repay the debt or at least pay the interest.
Conversely, if the debt is not as high, but the economy is in a moribund state, the government might get a slightly lower credit rating.