WASHINGTON (BLOOMBERG) - The Senate confirmed Antony Blinken as secretary of state, giving one of President Joe Biden's longest-serving aides the task of resuming nuclear negotiations with Iran, restoring trust with allies shaken by four years of Donald Trump and confronting an emboldened China and Russia.

Blinken, a former deputy secretary of state and Biden staffer on the Senate Foreign Relations Committee, was approved by a vote of 78-22 on Tuesday (Jan 26).

He was the latest of the president's national security team to be confirmed, following Director of National Intelligence Avril Haines and Defence Secretary Lloyd Austin.

Blinken, 58, will face no shortage of challenges on his first day.

He will help steer plans to re-enter the Iran nuclear deal over objections from many members of Congress, Israel and other US allies in the Persian Gulf.

And he must devise new ways to confront Russia, which has cracked down on supporters of jailed opposition leader Alexey Navalny, and China, which remains defiant despite a raft of sanctions targeting its rights abuses.

More broadly, he will try to persuade the rest of the world that US foreign policy will not reverse itself every time power changes hands in Washington.

That will be a tougher sell as the Biden administration seeks to undo Trump-era initiatives by halting plans to build a key gas pipeline with Canada, pressing Israel more over West Bank settlements and reconsidering support for populist leaders such as Hungarian leader Viktor Orban.

The incoming secretary pledged a bipartisan approach during his confirmation hearing last week, offering views aimed at mollifying Republican sceptics who said they fear he will simply seek to return to an Obama-era foreign policy.

He called China the "the most significant challenge of any nation-state to the United States" and said any re-entry to the Iran nuclear deal must be followed by a stronger, better agreement.

Blinken said at the hearing that his main job is to "show up again, day-in, day-out, whenever and wherever."

That's intended to reverse what Biden says was four years of neglect by Trump, who pulled the US out of the World Health Organisation, for example, and declined to back a global vaccine initiative.

Democratic Senator Robert Menendez of New Jersey called Blinken "the right person to repair and restore our alliances."

"The world is on fire right now, with pressing crises in every region and hemisphere," Menendez said on Monday night when the Senate Foreign Relations Committee approved Blinken's nomination.

"There will be more calamities like this, more emergencies that call for US leadership."

But Republican Senator Rand Paul of Kentucky said on Tuesday that Blinken and Biden represent an interventionist approach that led to the long and costly conflicts in Iraq and Afghanistan.

"If we're ever to end these wars, we're going to need to not keep nominating these retreads," Paul said on the Senate floor.

Under questioning from Republicans at the confirmation hearing, Blinken said he would seek "a longer and stronger agreement" on Iran. And he acknowledged that Trump's foreign policy led to favorable outcomes in some cases.

He cited a tougher approach to China, diplomatic deals between Israel and Arab states and increased defense spending from Nato partners as examples. He committed not to reverse Trump's decision to move the US Embassy in Israel to Jerusalem.

Biden's win was greeted with enthusiasm from some of those nations that bore the brunt of Trump's scorn, such as France and Germany.

Blinken will have a tougher job with American allies such as Israel, Saudi Arabia and the United Arab Emirates, which fear that in trying to return to the Iran deal the Biden administration will abandon them and jeopardise their security.

Close relationship

But other Republicans, inside and outside the Senate, pledged their support. They included Representative Michael McCaul, the top Republican on the House Foreign Affairs Committee, who said Blinken's testimony "highlighted many areas where we can work together to secure a more peaceful and prosperous world."

The decision to nominate Blinken was among the least surprising personnel moves Biden made. A Harvard graduate with decades of foreign policy experience, Blinken worked as Democratic staff director on the Senate Foreign Relations Committee when Biden was the top Democrat in the years before the Obama administration.

Blinken's close relationship with Biden will reassure foreign counterparts that he speaks for the president and US policy. Trump's first secretary of state, Rex Tillerson, lost credibility with the White House just months after taking office. He and former Secretary Michael Pompeo sometimes found themselves undercut by Trump's penchant for tweeting changes in US policy.

The continuing coronavirus pandemic means Blinken is unlikely to start overseas travel immediately, a Biden transition official, who asked not to be identified discussing private deliberations, told reporters this week.