Iran's Foreign Minister met Nicaraguan President Daniel Ortega, the South American country said, as the two allies seek to expand bilateral relations.
The countries, which are both subject to US sanctions, signed a deal on Wednesday for greater co-operation.
Foreign Minister Hossein Amirabdollahian will next head to Venezuela, Iran's Foreign Ministry said.
Mr Amirabdollahian held talks on Thursday with Mr Ortega who defended the rights of Iran and North Korea to develop nuclear weapons, saying Washington has no authority to restrict them.
“We don’t love atomic bombs … but what authority [do Western powers have] to want to prohibit Iran if it wants to make atomic bombs?” Mr Ortega asked with the Iranian minister by his side.
Mr Ortega said the West “don’t have the right to dictate who has and who doesn’t have atomic bombs”.
He said he would like “all atomic bombs to disappear”, starting with “the ones of the Yankees”, referring to the US.
Mr Amirabdollahian told Mr Ortega that Tehran’s nuclear programme has only peaceful aims.
This has been disputed by the US and other Western allies who signed an accord with Iran in 2015 to dismantle much of its nuclear programme.
Mr Amirabdollahian said Mr Ortega and Iranian President Ebrahim Raisi have committed to taking steps to put into effect a bilateral agreement signed at the end of 2022.
In December, Mr Amirabdollahian and Nicaragua Foreign Minister Denis Moncada signed an agreement in Tehran that included energy issues among others, although no details were shared.
On Wednesday evening, the two countries additionally signed a memorandum of understanding “for cultural, scientific, health co-operation, co-operation also in the political field and co-operation in all spheres of common good”, said Nicaraguan Vice President Rosario Murillo, who is also Mr Ortega's wife.
Mr Amir Abdollahian told reporters on Thursday that “yesterday we had and also today we are going to have important agreements between both countries”.
“The support of the parliaments of both countries is fundamental to implement the bilateral agreements,” he said.
Iran's Foreign Ministry said commercial and economic co-operation is a “priority” for the two countries, while political relations are at an “excellent” level.
Iran also maintains strong ties with Venezuela and Cuba, which are likewise subject to US-led international sanctions and have been widely criticised for their authoritarian regimes.