Sanctions are part of US campaign to raise economic pressure on Iran over its nuclear program.

The United States imposed sanctions on Wednesday on two networks it says helped boost Iran's nuclear program and evade US and international sanctions to benefit Tehran's government and military, the Treasury Department said.

One of the networks used a Hong Kong-based front company to avoid sanctions and target US technology and components on behalf of people tied to Iran's government and its Islamic Revolutionary Guard Corps, the US Treasury Department said in a statement.

The other network obtained aluminum alloy products controlled by the Nuclear Suppliers Group, a body that oversees the export of goods that can be used for nuclear weapons manufacturing, on behalf of companies owned or controlled by Iran's defense ministry, the department said.

The US Treasury Department also slapped sanctions on individuals connected to the two networks.

The sanctions are part of a US campaign to raise economic pressure on Tehran over its nuclear program.

Washington ditched a 2015 nuclear deal with Iran and five other countries, and has ratcheted up sanctions on Tehran, including imposing penalties on Iran's Foreign Minister Mohammad Javad Zarif. Zarif says he is unaffected by the sanctions.

On Monday, US President Donald Trump said at a news conference that he would be open to meeting with Iran's President Hassan Rouhani, but Rouhani has since said he would only be open to talks if Washington drops its sanctions against Tehran.