A senior US general says Iran's support for Houthi rebels extends to helping them target ships belonging to the Saudi-led coalition fighting in Yemen.
General Robert Ashley, Director of the Defence Intelligence Agency, told the Senate Armed Services Committee that "low-cost, high-payoff support" from Tehran has helped the Houthis "improve their military and missile capabilities, demonstrated through missile launches against targets in Saudi Arabia and Saudi-led coalition ships in the Red Sea".
This now includes "anti-ship missiles, explosive-laden boats, and mines," he said, making the Yemen war a "threat to vital international shipping lanes through the Red Sea".
Gen Ashley said Iran's regional goals were undiminished.
"Iran is poised to wield the most power in a post-conflict environment" in Syria, he said.
"We expect Iran to transition to efforts that secure and increase its long-term influence and to look for new opportunities to challenge its regional adversaries."
In Iraq, this will take form in Iran leveraging "its aligned PMF (Hasd Shaabi) and Shia militia groups, as well as its longstanding political and societal ties as its main avenues of influence to pressure Baghdad to expel US and coalition forces and prevent Kurdish separatism".
As the ISIL territorial threat recedes, Shia militia groups, including those loyal to Iran, "are likely to pose an increasing threat to US forces", the general said.
And in Syria, Iran's presence "not only benefits the (Bashar Al) Assad regime, it represents a key step toward Iran's goal of a land bridge from Tehran through Iraq and Syria into Lebanon".
Gen Ashley said that after the nuclear deal - known as the Joint Comprehensive Plan of Action (JCPOA) - agreed in 2015 but enacted in January the following year, the Iranian government increased funding to its security forces. However, with the latest protests in Iran driven by economic difficulties, the US commander said spending on domestic programmes will remain the priority for Tehran in the near term.
With regard to Iran's military capabilities, Gen Ashley said that in 2017, Tehran tested and fielded its Russian-made SA-20c surface-to-air missile system.
In the long run, "Tehran is pursuing long-range, precision land-attack cruise missiles, which present a new type of threat in the region" and "is also developing more powerful space launch vehicles and technologies that enable development of long-range missile subsystems", he said.
His testimony came as President Donald Trump's government is consulting with regional partners on a counter-Iran strategy, and with European powers on measures to amend few provisions in the JCPOA or otherwise abandon it in May.