The National Liberation Army (Albanian: Ushtria Çlirimtare Kombëtare -UÇK), also known as the Macedonian UÇK, not to be confused with the Kosovar UÇK - Ushtria Çlirimtare e Kosovës - the Kosovo Liberation Army, is a terrorist organization that operates in the Republic of Macedonia. The NLA was founded in the fall of 1999, and was led by Ali Ahmeti, the nephew of Fazli Veliu , founder of the KLA, but was out of the public eye until it began to openly commit large scale crimes 2000 and 2001. In March 2001, when the majority Albanian population in Tetovo, the second largest city in Macedonia, was attacked, NLA members were unable to take Tetovo, but controlled the hills and mountains between Tetovo and Kosovo. NLA was also supported by incursions from Kosovo, so the links to KLA and UCPMB was obvious, but never officially admitted.

The Macedonian NLA consists of ethnic Albanians (of which many were probably former KLA members) seeking to gain greater political and economic freedom in western Macedonia. Some allege that the NLA is in favor of a Greater Albania in which western Macedonia would become part of Albania again.

After the Ohrid Agreement, the NLA agreed to cease-fire in June. Under the Ohrid Agreement, the Macedoniana government pledged to improve the rights of the Albanian population, that makes up just over 25 per cent of the population. Those rights include making Albanian language an official language, increasing the participation of ethnic Albanians in government institutions, police and army. Also, under this agreement the University of Tetovo was to be recognised.

Most importantly, under the Ohrid Agreement, Macedonian government agreed to a new model of decentralisation. This process in ongoing.

In addition, according to this accord the NLA was to disarm and hand over their weapons to a NATO force.

Operation "Essential Harvest" was officially launched on 22 August and effectively started on 27 August. This 30-day mission involved approximately 3500 NATO troops to disarm the NLA and destroy their weapons. Just hours after NATO wrapped up the operation, Ali Ahmeti told reporters attending a news conference in the rebel stronghold of Sipkovica that he was dissolving the National Liberation Army and that it was time for ethnic reconciliation.