The phrase "proclaimed in a speech" is correct and usable in written English
You can use it when referring to a statement that was spoken aloud, usually delivered in a formal or public setting. For example: "The president proclaimed in a speech that all taxes will be lowered."
He instead proclaimed in a speech that Sevastopol, the site of the Russian naval base, belongs to Russia.
"As we have witnessed so clearly in recent years, advances in technology have enhanced the growth in productivity, which in turn has been essential to lifting our standards of living," Mr. Greenspan proclaimed in a speech this month.
Defending Labour's recent tilt towards cuts, Ed Miliband proclaimed in a speech on 10 January that "the next prime minister will still have a deficit to reduce, and will not have money to spend".
"Iran has already become a nuclear country and no one is capable of stealing this title," the president, Mahmoud Ahmadinejad, proclaimed in a speech in Tehran during a ceremony commemorating National Nuclear Technology Day, a holiday he created in 2006 during his first term in office to trumpet Iran's nuclear energy achievements.
As he proclaimed in a speech at the Republican National Convention: "Of course, every American has a unique identity.
Mr Obama proclaimed in a speech to cadets at West Point that isolation is not an option and that regional aggression cannot go unchecked.
In the aftermath of his unexpected victory, David Cameron chose to highlight his commitment to the NHS, proclaiming in a speech of upbeat optimism that "we can become the first country in the world to deliver a truly seven-day NHS".
In 2010, Camp vowed to take up tax reform as his life's work, proclaiming in a speech before the Tax Council, "I aim to launch and fight the tax reform battle once again.
They will ascend a monumental stair to all? of 150 linden trees flanking a sloped lawn and culminating in a granite-lined open-air plaza called the room, which will house a bust of the former president and will be engraved with the Four Freedoms (of speech and religion, and from want and fear) he proclaimed in a 1941 speech.
In 2001 Larry Ellison brashly proclaimed in a keynote speech at the computing conference Comdex that his database software was "unbreakable".
With this action he practically said, 'I don't care if the two hostages die,' " Mitsuhiro proclaimed in a street speech in Shinjuku assailing Abe's handling of the emergency.
