The phrase "asserting at" is not correct and does not convey a clear meaning in written English.
It is not commonly used and may lead to confusion; it would be better to use it in a context where you are indicating a specific point or situation of assertion.
Example: "The researcher is asserting at the conference that new methods are needed for data analysis."
Alternatives: "claiming at" or "stating at".
The candidates themselves engaged in one of their first direct exchanges over the weekend, with Mr. Romney asserting at a debate Saturday that Iran's progress toward developing a nuclear weapon represented Mr. Obama's "greatest failing".
He admits enough of its iniquities to inspire confidence in his readers and omits enough to spare their sensibilities, while asserting, at the same time, the virtues which acquit the British of really criminal imperialism.
Russian officials provided an alternative account, asserting at the time that Mr. Trump had accepted Mr. Putin's denial of the election interference and even said that some in the United States were "exaggerating" Moscow's role without proof.
Mr. Wahid denounced the vote as unconstitutional and for three days refused to vacate the presidential palace, asserting at one point that Mrs. Megawati would have to evict him.
But later, with an increase in violent attacks by Uighurs, the party changed course, asserting at a major meeting on the region in 2014 that the priorities were stability and unity rather than economic development and combating discrimination.
President Clinton was also on script, asserting at a news conference here that the court's stand on abortion was "very much in the balance, depending on what appointments are made in the next four years".
Statistical significance was asserted at the 5% level (p < 0.05).
1203, 1 L.Ed.2d 1311, where the specific grounds sustained by the Court were vigorously asserted at the hearing.
"We lopped 400,000 off the welfare rolls," he asserted at several stops.
UBS certainly asserted at the Tennessee trial that it was willing to talk.
Dumbledore is, as his creator, J. K. Rowling, asserted at Carnegie Hall, gay.
