unilateral
adjective
uk/ˌjuːnɪˈlætərəl/ usdone by only one of the groups, organizations, or countries involved in an activity or process:
More than 70 developing countries have undertaken unilateral trade liberalization initiatives during the last 20 years.
Opponents of the government have criticized the president's unilateral approach and believe broader international alliances are required.
unilateral actions/decisions/concessions
unilaterally
adverb
decisions taken unilaterally