Uganda's government says it is preparing a response to the court challenge filed by a lawyers' association against a new law removing a presidential age limit from the constitution.

The change allows 73-year-old President Yoweri Museveni to run for another term in 2021. The opposition has loudly protested the change, and the Uganda Law Society on Monday filed a petition arguing that it should be annulled and alleging that the process was flawed.

The Uganda Media Center's executive director, Ofwono Opondo, says the attorney general is working on a reply, adding that "we have no problem with people who go to court to challenge this legislation."

Museveni, who took power by force in 1986, is the latest African leader to prolong his time in office by changing the constitution.