U.S. Secretary of State John Kerry has urged Iran to use its influence to help end the wars in Yemen and Syria rather than pursue "destabilizing" activities in the region.
At a news conference in Bahrain as he visited U.S. allies in the Persian Gulf on April 7, Kerry condemned "the destabilizing actions of Iran, which the United States takes very seriously."
He noted that the U.S. Fifth Fleet, which is based in Bahrain, last week seized a cache of weapons which the U.S. Navy said Iran was shipping to Huthi rebels in Yemen to help in their war against the government.
"We call on Iran to constructively join in the efforts to make peace and to help us to resolve Syria. Rather than to continue to send weapons to Huthis, join in the effort...to make peace and to work toward a cessation of hostilities," Kerry said.
While visiting with Iran's fierce rivals in the Gulf, Kerry defended Tehran's nuclear accord with world powers and the lifting of economic sanctions under the accord, which is giving a boost to Iran's economy.
But he stressed that the United States and its Arab allies "remain united in our opposition to Iran's missile activities."
The United States has imposed a series of sanctions on Iran over its ballistic-missile tests and has urged the United Nations Security Council to also sanction Iran. That has prompted strenuous objections from Tehran, which says such sanctions undermine the economic relief it is entitled to under the nuclear accord after having curbed its nuclear development activities.
Kerry on April 7 said for the first time the United States is open to a "new arrangement" with Iran for peacefully resolving disputes over the missile tests, AP reported.
Without elaborating, Kerry said the United States and its allies have told Iran that they are "prepared to work on a new arrangement to find a peaceful solution to these issues."
But he said Iran first had to "make it clear to everybody that they are prepared to cease these kinds of activities that raise questions about credibility and questions about intentions."
In an address on state television on April 7, Rohani said: "We are in favor of a policy of moderation...Iran is not a threat to any country...Tehran wants interaction with the world, with its neighboring countries.
"With moderation we can reach our goals faster...To progress, we need to have interaction with the world," he continued.
But Bahraini Foreign Minister Sheikh Khalid bin Ahmed Al-Khalifa, whose government accuses Iran of stoking protests among the kingdom's Shi'ites demanding an end to Sunni minority rule, echoed Kerry's call for more cooperation from Tehran.
Iran's "interventions through proxies in several parts of our region [are] continuing unabated," he said.
Saudi Foreign Minister Adel al-Jubeir called for a complete halt to Iranian support for the Huthi rebels in Yemen.
"If Iran continues its aggressive policy," he said, "it will be difficult to deal with Iran."
Tehran argues that it is Saudi Arabia and its Gulf allies that are sowing instability in the region with their air strikes supporting the government in Yemen and their financial backing for opposition forces in Syria.
The war in Yemen is at a critical junction, like the Syrian war, where a serious effort at forging peace sponsored by the United Nations is under way.
Yemen's warring parties have agreed to observe a UN-brokered cease-fire starting at midnight April 10, and peace negotiations are due to start in Kuwait on April 18.
As in Syria, the war has had a devastating impact on the people of Yemen. The United Nations says around 6,300 people have been killed in the war.
The bombardment of Yemen by a Saudi-led Arab coalition has taken a particularly devastating toll. Human Rights Watch said on April 7 that bombs supplied by the United States were used in coalition air strikes on a market in Yemen that killed at least 97 civilians, including children, last month.
Kerry declined to comment on that accusation.
In Syria, Iran and the Gulf Arab states are also on opposing sides of the war. Iran has been a principle backer of President Bashar al-Assad's regime while the Arab states have supported rebel groups seeking to oust Assad.
That five-year war has killed more than 270,000 people and pushed nearly 5 million into exile. The United States has been trying to galvanize support behind UN-sponsored peace talks that are set to resume on April 13 in Geneva.
As in past efforts at Syrian peace, Kerry said the main obstacle is deciding Assad's future. Rebel groups want Assad to step down during a political transition leading to elections.
But Assad -- backed by Iran and Russia -- insists on at least sharing power until the elections, when voters will decide on his fate and a new government.
"The discussion about transition is the key test of the seriousness of the Assad regime, of Russia and Iran" about peace in Syria, Kerry said.