The meetings came a day after Rouhani was inaugurated for a second term during a ceremony attended by more than 100 foreign delegates.
Speaking with Armenian President Serzh Sargsyan, Rouhani said Iran is trying to bolster ties with its neighboring countries, including Armenia.
He said the two countries can work together in many areas including economy, tourism, transport and culture.
Rouhani underlined the importance of security and stability in the region and sounded the alarm about terrorisms.
“After suffering a complete defeat in Iraq and Syria, terrorists are likely to try to permeate across the region. Thus, all of us should be aware of such a threat (in the region), as in the Caucasus and Central Asia,” Rouhani said.
It is necessary for all regional countries to coordinate efforts in the fight against terrorism, a challenge that threatens the security of the entire region, he added.
The Armenian president, for his part, congratulated Rouhani on taking office for the second term, voicing his country’s readiness to enhance economic relations with Iran.
Sargsyan called for efforts to raise the level of Tehran-Yerevan trade ties, pointing to the opportunities available for cooperation in the energy industry and transportation.
Support for Lebanon
Rouhani also met with Lebanon's Parliament Speaker Nabih Berri. The president reiterated Iran’s policy to continue backing the Lebanese people and government and stressed the need for closer relations between the two Middle Eastern nations in all areas.
Rouhani hailed bilateral ties as “friendly and brotherly” and said the Lebanese people have a special place in the hearts of the Iranian people.
He further hailed the unity among Shia and Sunni Muslims and Christians in Lebanon as a role model for other countries with multiple communities.
“Today, the Lebanese people consider Hezbollah and the country’s army as powers providing security,” Rouhani said.
“The Islamic Republic of Iran has always sided with the government, people, and resistance [movement] of Lebanon and will keep on the same path in the future,” he added.
Berri underlined that Iran is currently a powerful and glorious country in the region, adding that the Islamic Republic will never be alone.
EU key role
In a meeting with Spanish Senate President Pio Garcia-Escudero, Rouhani said the 2015 Iran nuclear deal with world powers helped the country boost its economic cooperation with European nations.
He hailed the European Union for its “significant role” in implementing the landmark deal despite the US wrench-throwing.
The Spanish official pointed to Iran’s “outstanding positon” in the region, saying it is the result of the Iranian government’s policies which have also boosted the country’s economy.
Rouhani and Zarif met with other visiting officials, shown in photos that follow.