The phrase "assert its sovereignty" is correct and usable in written English.
It can be used in contexts discussing a nation or entity claiming or demonstrating its independence and authority.
Example: "The country sought to assert its sovereignty in the face of external pressures and influence."
Alternatives: "claim its independence" or "exercise its authority".
Canada, in particular, feels that it must assert its sovereignty over what it regards as its share of the Arctic and has beefed up its military measures in the region.
That would allow it to assert its sovereignty and save face after years of diplomatic tensions.
For Sindh which had been subject to Mughal rule from 1591 onwards, the erosion of imperial authority in Delhi meant an opportunity for it to assert its sovereignty.
For the government, it is a way to assert its sovereignty and prove to its citizens that it is not reliant on foreign forces.
Because of decades of campaigning by a population determined to assert its sovereignty.
Meanwhile, Israeli coalition members have backed the project and urge the government to assert its "sovereignty" over the sacred site.
Gershom Gorenberg puts the post-1967 issue with great clarity in his fine book, "The Unmaking of Israel": "If Israel really believed that the territorial division created by the 1949 armistice was null and void, it could have asserted its sovereignty in all of former Palestine — and granted the vote and other democratic rights to all inhabitants".
The government claimed it was simply addressing longstanding immigration issues and asserting its sovereignty to manage citizenship.
That is not to say that China has refrained from asserting its sovereignty claims.
Conversely, the architecture in Ray Germann's classic details of New York City seems to defy change, asserting its sovereignty over unruly nature.
The exercises come at a time when China is expanding the mission of its navy and asserting its sovereignty over waters claimed by other Asian nations.
