Libertarian presidential nominee Gary Johnson is "really optimistic" that he will soon join Donald Trump and Hillary Clinton on stage for the first of three presidential debates this fall.

"The Presidential Debate Commission identified five polls, we're at 10 percent flat on those five polls and that's an increase really of probably about 4 percent consensus over the last six or seven weeks," Johnson told Fox News' Chris Wallace on Sunday.

"So we're optimistic that we're going to get into the debates," he said, noting that his campaign is spending money on advertisements in several states and he's reached 16 percent support in some.

Nevertheless, Johnson is not where he needs to be. According to criteria released by the Presidential Debate Commission, Johnson would have to reach 15 percent support among the national electorate to be eligible to participate in the three presidential debates. The commission will use five national polls to determine each candidate's eligibility.

The first presidential debate is slated to take place in Hempstead, N.Y. on Sept. 26.