Republican lawmaker seeks impeachment vote against Defence Secretary Pete Hegseth

Republican US Representative Thomas Massie has taken steps to force a vote in Congress on impeaching Defence Secretary Pete Hegseth, accusing the Pentagon chief of exceeding his constitutional authority in the conduct of military operations.

Massie, a prominent Republican critic of the Trump administration's war on Iran, read articles of impeachment against Hegseth on the floor of the US House of Representatives on Tuesday.

The Kentucky congressman accused Hegseth of waging war without congressional authorisation, carrying out extrajudicial killings and failing to give sufficient consideration to civilian casualties during US military operations.

Massie said Hegseth had abused the authority granted to him as defence secretary by putting his own policy objectives ahead of constitutional restrictions on the use of military force and laws governing armed conflict.

He also accused Hegseth of showing a "profound disregard" for the consequences of US military operations for civilians.

Hegseth has faced criticism over his handling of the US-Israel war on Iran and previous comments about rules designed to protect civilians and ensure US forces comply with the law.

The defence secretary has previously described some rules of engagement intended to limit civilian casualties as "stupid" and "politically correct", arguing that they can restrict military operations.

Massie's impeachment resolution could be brought to a vote in the House in the coming days. However, the measure faces significant political obstacles in the Republican-controlled chamber.

The Pentagon has expressed its support for Hegseth.

"The entire Department is unified behind the Secretary's vision and will continue working to put our warfighters and America first," Pentagon press secretary Kingsley Wilson said in a statement.

Massie's move comes amid divisions among Republicans over the Trump administration's foreign policy. While polling has indicated broad Republican support for the war on Iran, some figures on the political right, including Massie and media personality Tucker Carlson, have publicly criticised the administration's interventionist approach.

President Donald Trump has previously criticised Massie over his opposition to the Iran war and his efforts to compel the government to release files relating to Jeffrey Epstein.

Massie lost his Republican primary in May to a Trump-backed challenger, following a campaign that also attracted substantial spending from pro-Israel groups.