[9] On 26 March 2008, the Government of Serbia announced its plan to call on the International Court of Justice to rule on the declaration of Kosovo's secession.

[10] On 15 August 2008, Serbian Foreign Minister Vuk Jeremić officially filed a request at the United Nations seeking opinion of the International Court of Justice.

[11] The resolution was worded as follows: The General Assembly, Mindful of the purposes and principles of the United Nations, Bearing in mind its functions and powers under the Charter of the United Nations, Recalling that on 17 February 2008 the Provisional Institutions of Self-Government of Kosovo declared independence from Serbia, Aware that this act has been received with varied reactions by the Members of the United Nations as to its compatibility with the existing international legal order, Decides, in accordance with Article 96 of the Charter of the United Nations to request the International Court of Justice, pursuant to Article 65 of the Statute of the Court to render an advisory opinion on the following question: On 30 September 2008, in a trial vote, the Serbian initiative was backed by 120 member states.

[15] The 77 countries that voted for the initiative A/63/L.2 of Serbia were: Algeria, Angola, Antigua and Barbuda, Argentina, Azerbaijan, Belarus, Bolivia, Botswana, Brazil, Brunei, Cambodia, Chile, China, Costa Rica, Cuba, Cyprus, Democratic Republic of the Congo, Djibouti, Dominica, Dominican Republic, East Timor, Egypt, El Salvador, Equatorial Guinea, Eritrea, Fiji, Greece, Guatemala, Guinea, Guyana, Honduras, Iceland, India, Indonesia, Iran, Jamaica, Kazakhstan, Kenya, Kyrgyzstan, Lesotho, Liechtenstein, Madagascar, Mauritius, Mexico, Montenegro, Myanmar, Namibia, Nicaragua, Niger, Nigeria, North Korea, Norway, Panama, Papua New Guinea, Paraguay, Philippines, Republic of the Congo, Romania, Russia, Saint Vincent and the Grenadines, Serbia, Singapore, Slovakia, Solomon Islands, South Africa, Spain, Sri Lanka, Sudan, Suriname, Swaziland, Syria, Tanzania, Uruguay, Uzbekistan, Vietnam, Zambia and Zimbabwe.

The 74 countries that abstained from voting were: Afghanistan, Andorra, Armenia, Australia, Austria, Bahamas, Bahrain, Bangladesh, Barbados, Belgium, Belize, Benin, Bhutan, Bulgaria, Burkina Faso, Cameroon, Canada, Colombia, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Georgia, Germany, Ghana, Grenada, Haiti, Hungary, Ireland, Israel, Italy, Japan, Jordan, Latvia, Lebanon, Lithuania, Luxembourg, Macedonia, Malaysia, Malta, Moldova, Monaco, Mongolia, Morocco, Nepal, the Netherlands, New Zealand, Oman, Pakistan, Peru, Poland, Portugal, Qatar, Saint Lucia, Samoa, San Marino, Saudi Arabia, Senegal, Sierra Leone, Slovenia, South Korea, Sweden, Switzerland, Thailand, Togo, Trinidad and Tobago, Uganda, Ukraine, United Arab Emirates, United Kingdom, Vanuatu, and Yemen.

Officially the following countries were absent: Bosnia and Herzegovina, Burundi, Cape Verde, Chad, Côte d'Ivoire, Ecuador, Ethiopia, Gabon, Gambia, Iraq, Kiribati, Kuwait, Laos, Libya, Malawi, Maldives, Mali, Mauritania, Mozambique, Rwanda, Saint Kitts and Nevis, Seychelles, Tonga, Tunisia, Turkey, Turkmenistan, Tuvalu and Venezuela.

The following states were not allowed to vote due to the lack of payments to the UN: Central African Republic, Comoros, Guinea Bissau, Liberia, São Tomé and Príncipe, Somalia and Tajikistan.

Also included were 'general international law instruments – universal and regional', such as copies of the UN Charter, Helsinki Final Act, and various agreements on civil and human rights, as well as other legal documents from the wider Balkans (such as the rulings of the Badinter Commission).

[19] Written statements were submitted by the following states (in order of receipt): the Czech Republic,[19] France,[20] Cyprus,[19] People's Republic of China,[19] Switzerland,[19] Romania,[19] Albania,[21] Austria,[22] Egypt,[23] Germany,[19] Slovakia,[19] Russia,[19] Finland,[24] Poland,[25] Luxembourg,[26] Libya,[27] the United Kingdom,[19] the United States of America,[19] Serbia,[19] Spain,[19] Iran,[28] Estonia,[29] Norway,[30] the Netherlands,[19] Slovenia,[19] Latvia,[31] Japan,[32] Brazil,[33] Ireland,[19] Denmark,[19] Argentina,[19] Azerbaijan,[19] Maldives,[34] Sierra Leone,[19] and Bolivia.

Ban writes about provisions of international law relevant to the case in the third part of his written statement, without expressing his position in favour of or against the province's independence.

[44] At the end of public hearings, judges Abdul Koroma, Mohamed Bennouna and Antônio Augusto Cançado Trindade gave all parties until 22 December 2009, to answer questions related to claims that international law does not prohibit secession, regarding promises by participants of the parliamentary elections in Kosovo in 2007 to declare independence and the provisions of the Rambouillet accords from 1999.

As UNSCR 1244 vested all authority in Kosovo in the Special Representative of the Secretary-General, the argument is that the Provisional Institutions had no power to declare independence.

[79] It ultimately also led to increased tensions in Bosnia-Herzegovina, where Republika Srpska vetoed the Kosovo recognition[80] on the ground that it would then secede in order to make up for the loss to Serbia.

[81] The ICJ itself limited the scope of its decision by stating that it "is not required by the question it has been asked to take a position on whether international law conferred a positive entitlement on Kosovo unilaterally to declare its independence or, a fortiori, on whether international law generally confers an entitlement on entities situated within a State unilaterally to break away from it" .

"[84] The Belgian Foreign Minister Steven Vanackere also reiterated his call in that he "hopes that all the parties concerned will react responsibly and will take on board the opinion of the International Court of Justice".

"[86] Prior to the judgment, US Vice President Joe Biden said that the U.S. would not contemplate a retreat from Kosovo's independent status,[81] while he also sought to reassure the Kosovar Prime Minister of the U.S.'s support.

[87] While State Department legal adviser Harold Koh said "Serbia seeks an opinion by this court that would turn back time ... [and] undermine the progress and stability that Kosovo's declaration has brought to the region.

[citation needed] Nonetheless, the Court determined that the declaration of independence was not issued by the Assembly of Kosovo or otherwise by Provisional Institutions of Self-Government or any other official body.

[citation needed] In finding this, the Court referred to the fact that the declaration did not follow the legislative procedure; and was not properly published.

Serbian reactions were negative to the verdict while policymakers met in an emergency session to discuss Serbia's next steps to preserve its territorial integrity while vowing never to recognise Kosovo as an independent state, despite Kosovar calls to the contrary.