Australia`s Constitution allows the executive government to enter into contracts, but it is customary for contracts to be presented in both houses of Parliament at least 15 days before signing. Treaties are considered a source of Australian law, but sometimes require the adoption of a parliamentary act based on their nature. Contracts are managed and maintained by the Department of Foreign Affairs and Trade, which stated that the “general position under Australian law is that contracts to which Australia has joined, with the exception of those that end a state of war, are not directly and automatically included in Australian law. Signing and ratification do not allow treaties to operate on national territory. In the absence of legislation, contracts cannot impose obligations on individuals or create rights in national law. Yet international law, including contract law, is a legitimate and important influence on the development of the common law and can be used in the interpretation of laws.  Treaties can be implemented by executive measures and existing laws are often sufficient to ensure compliance with a treaty. Currently, the likelihood of international agreements being implemented by an executive agreement is ten times higher. Despite the relative simplification of executive agreements, the President still often chooses to continue the formal process of concluding an executive agreement in order to gain congressional support on issues that require Congress to pass appropriate enforcement laws or means, as well as agreements that impose complex long-term legal obligations on the United States. For example, the agreement of the United States, Iran and other countries is not a treaty. Under international law, a treaty is a legally binding agreement between states (countries). A treaty can be called a convention, protocol, pact, agreement, etc. It is the content of the agreement, not its name, that makes it a treaty.
Thus, the Geneva Protocol and the Biological Weapons Convention are the two treaties, although neither treaty in its name. Under U.S. law, a treaty is a legally binding agreement between countries that requires ratification and “consultation and approval” of the Senate. All other agreements (internationally treated) are called executive agreements, but are nevertheless legally binding on the United States under international law. International contract law has been largely codified by the Vienna Convention on Treaty Law, which sets out the rules and procedures governing the establishment, modification and interpretation of contracts, as well as the resolution and resolution of disputes and alleged infringements.  Treaties are considered to be one of the oldest manifestations of international relations as the main source of international law.  According to the preamble to contract law, treaties are a source of international law.