The phrase "asserted at the" is grammatically correct and can be used in written English.
It is typically used in contexts where a statement or claim is being made or emphasized, often followed by a specific location or context.
Example: "The findings were asserted at the conference, highlighting the importance of the research."
Alternatives: "stated at the" or "declared at the".
UBS certainly asserted at the Tennessee trial that it was willing to talk.
And, as many asserted at the time, the vetting process of the vice-presidential candidate appears to have taken just a few scant days.
Mr. Frist also asserted at the time that "for the past 18 years, Jim Sasser has been transplanting your wallets and your pocketbooks to Washington, D.C".
"It is time to come together in a new international agreement that can embrace the rich and poor nations alike," he asserted at the meeting.
The Christological position called monophysitism asserted that in the person of Jesus Christ there was only one, divine nature rather than two natures, divine and human, as asserted at the Council of Chalcedon in 451.
"We didn't come here to spend all our time cutting deficits created by Republicans," she asserted at the time, according to Carl Bernstein's recent Hillary biography, "A Woman in Charge".
But she asserts at the end that 'an individual life is interesting enough to merit examination' and her book is testament to this.
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.
While the group takes pains to say it has nothing against Muslims, who "can be and usually are peaceful and respectful," it asserts at the start: "The Quran contains many lies and threats.
The 2-5 favourite was asked to assert at the second-last but Knockara Beau, who lowered the colours of the great Big Buck's in the Cleeve Hurdle last month, refused to go away quietly.
This device allows events to unfold hesitantly as the composite 'truth' of events emerges, truth which leads Robert to assert at the novel's end: 'I understood only that I had understood nothing.
