Iraqi Prime Minister Adel Abdul Mahdi is on a two-day visit to neighboring Iran as the countries seek to expand commercial ties.
Mahdi met President Hassan Rohani in Tehran on April 6, with the Iranian leader saying they discussed expanding their gas and electricity trade and working towards fulfilling a plan to connect their railroads.
Mahdi's visit came after Rohani made his first official visit to Iraq in March, with Tehran seeking to bolster its influence in its neighboring country as Baghdad is under pressure from the United States to limit ties with Iran.
Iraq, which receives financial and military support from Washington, has attempted to balance its relations with the United States and Iran, which carries significant influence with members of Iraq's Shi'ite population.
Tehran does not have an official military presence in Iraq. But the government supports powerful Shi'ite paramilitary groups operating in the country, with estimates of the number of fighters ranging up to 150,000.
The United States has some 5,200 troops stationed in Iraq, mostly focused on training and support missions.
The United States has called on Baghdad to form partnerships with American companies to become energy independent.