US Secretary of State John Kerry has urged Congress to end the partial government shutdown and think "long and hard" about the message US sends the world when "we can't get our own act together".

Kerry is in Bali for an economic summit of Asian leaders.

President Barack Obama had planned to attend, but cancelled to remain in Washington and deal with the shutdown, which went into effect on Tuesday. Kerry is now heading the US delegation in the talks.

Kerry said yesterday that the US's "friends and foes" around the world shouldn't mistake the government shutdown for anything other than a "moment of politics".

"When we get this moment of political silliness behind us, we will get back on a track the world will respect and want to be part of," he said at a news conference.

He called on recalcitrant lawmakers to "end it now, end it today".

Kerry vowed that the US would fulfil its responsibilities during the partial shutdown that has crippled large parts of the federal government and locked thousands of government employees out of their offices.

But he noted that security assistance to critical allies such as Israel may be affected and that the Treasury Department's Office of Foreign Assets Control, which oversees sanctions on countries such as Iran, had been forced to furlough nearly all of its staff.

He stressed that he believed the shutdown would not be long term.

Kerry rejected the notion that the shutdown and Obama's cancellation of his summit trip was a sign of "weakness".