As stated in Article 93 of the UN Charter, all UN members are automatically
parties to the court's statute. Non-UN members may also become parties to the court's statute under the Article 93(2) procedure, which was used by Switzerland in 1948 and Nauru in 1988, prior to either joining the UN. Once a state is a party to the court's statute, it is entitled to participate in cases before the court. However, being a party to the statute does not automatically give the court jurisdiction over disputes involving those parties. The issue of
jurisdiction is considered in the three types of ICJ cases: contentious issues, incidental jurisdiction, and advisory opinions.
Contentious issues In contentious cases (adversarial proceedings seeking to settle a dispute), the ICJ produces a binding ruling between states that agree to submit to the ruling of the court. Only
states may be parties in contentious cases; individuals, corporations, component parts of a federal state, NGOs, UN organs, and
self-determination groups are excluded from direct participation, although the court may receive information from public
international organizations. However, this does not preclude non-state interests from being the subject of proceedings; for example, a state may bring a case on behalf of one of its nationals or corporations, such as in matters concerning diplomatic protection. Jurisdiction is often a
crucial question for the court in contentious cases. The key principle is that the ICJ has jurisdiction only on the basis of consent. Under Article 36, there are four foundations for the court's jurisdiction: •
Compromis or "special agreement", in which parties provide explicit consent to the court's jurisdiction by referring cases to it. While not true compulsory jurisdiction, this is perhaps the most effective jurisdictional basis, because the parties concerned have a desire for the dispute to be resolved by the court, and are thus more likely to comply with the court's judgment. • Compromissory clauses in a binding treaty. Most modern
treaties contain such clauses to provide for dispute resolution by the ICJ. Cases founded on compromissory clauses have not been as effective as cases founded on special agreement, since a state may have no interest in having the matter examined by the court and may refuse to comply with a judgment. For example, during the
Iran hostage crisis, Iran refused to participate in a case brought by the US based on a compromissory clause contained in the
Vienna Convention on Diplomatic Relations and did not comply with the judgment. Since the 1970s, the use of such clauses has declined; many modern treaties set out their own dispute resolution regime, often based on forms of
arbitration. • Optional clause declarations accepting the court's jurisdiction. Also known as Article 36(2) jurisdiction, it is sometimes misleadingly labeled "compulsory", though such declarations are voluntary. Many such declarations contain reservations that exclude from jurisdiction certain types of disputes (
ratione materia). The principle of
reciprocity may further limit jurisdiction, as Article 36(2) holds that such declaration may be made "in relation to any other State accepting the same obligation...". As of January 2018, seventy-four states had a declaration in force, up from sixty-six in February 2011; In the court's early years, most declarations were made by industrialized countries. Since the 1986
Nicaragua case, declarations made by developing countries have increased, reflecting a growing confidence in the court. However, even those industrialized countries that have invoked optional declarations have sometimes increased exclusions or rescinded them altogether. Notable examples include the
United States in the Nicaragua case, and Australia, which modified its declaration in 2002 to exclude disputes on
maritime boundaries, most likely to prevent an impending challenge from East Timor, which gained independence two months later. • Article 36(5) provides for jurisdiction on the basis of declarations made under the Statute of the
Permanent Court of International Justice. Article 37 similarly transfers jurisdiction under any compromissory clause in a treaty that gave jurisdiction to the PCIJ. Additionally, the court may have jurisdiction on the basis of tacit consent (
forum prorogatum). In the absence of clear jurisdiction under Article 36, jurisdiction is established if the respondent accepts ICJ jurisdiction explicitly or simply pleads
on the merits. This arose in the 1949
Corfu Channel Case (U.K. v. Albania), in which the court held that a letter from Albania stating that it submitted to the jurisdiction of the ICJ was sufficient to grant the court jurisdiction.
Incidental jurisdiction Until rendering a final judgment, the court has competence to order interim measures for the protection of the rights of a party to a dispute. One or both parties to a dispute may apply the ICJ for issuing interim measures. In the
Frontier Dispute Case, both parties to the dispute,
Burkina Faso and
Mali, submitted an application to the court to indicate interim measures. Incidental jurisdiction of the court derives from the Article 41 of its Statute. Similar to the final judgment, the order for interim measures of the court are binding on state parties to the dispute. The ICJ has competence to indicate interim measures only if the
prima facie jurisdiction is satisfied.
Advisory opinions by the Provisional Institutions of Self-Government of Kosovo" An
advisory opinion is a function of the court open only to specified United Nations bodies and agencies. The UN Charter grants the General Assembly or the Security Council the power to request the court to issue an advisory opinion on any legal question. Organs of the UN other than the General Assembly or the Security Council require the General Assembly's authorization to request an advisory opinion of the ICJ. These organs of the UN only request an advisory opinion regarding the matters that fall within the scope of their activities. On receiving a request, the court decides which states and organizations might provide useful information and gives them an opportunity to present written or oral statements. Advisory opinions were intended as a means by which UN agencies could seek the court's help in deciding complex legal issues that might fall under their respective mandates. In principle, the court's advisory opinions are only consultative in character but they are influential and widely respected. Certain instruments or regulations can provide in advance that the advisory opinion shall be specifically binding on particular agencies or states, but inherently they are non-binding under the Statute of the court. This non-binding character does not mean that advisory opinions are without legal effect, because the legal reasoning embodied in them reflects the court's authoritative views on important issues of international law. In arriving at them, the court follows essentially the same rules and procedures that govern its binding judgments delivered in contentious cases submitted to it by sovereign states. An advisory opinion derives its status and authority from the fact that it is the official pronouncement of the principal judicial organ of the United Nations. Advisory opinions have often been controversial because the questions asked are controversial or the case was pursued as an indirect way of bringing what is really a contentious case before the court. Examples of advisory opinions can be found in the section
advisory opinions in the
List of International Court of Justice cases article. One such well-known advisory opinion is the
Nuclear Weapons Case. On 23 July 2025, the court issued an advisory opinion regarding the State obligations in respect of
climate change, upon request by the
General Assembly to address two questions: the obligations of States under international law to protect the climate system from anthropogenic emissions for States and for present and future generations, and the legal consequences arising where states, by their acts and omissions, have caused significant harm to the climate system and other parts of the environment. This was the biggest case in the history of the court, with 99 countries and more than 12 intergovernmental organizations heard over two weeks in December 2024. ==Examples of contentious cases==