By Trevor Hunnicutt and Humeyra Pamuk

WASHINGTON (Reuters) – U.S. Vice President Kamala Harris and Secretary of State Antony Blinken face a tough task at the annual Munich Security Conference that kicks off on Friday – reassuring allies the United States remains committed to defending their security.

Harris and Blinken are set to attend the annual security gathering less than a week after former U.S. President Donald Trump, the frontrunner for the Republican presidential nomination, said he would not defend NATO allies who failed to spend enough on defense.

U.S. President Joe Biden, a Democrat, and Trump are locked in a tight election rematch in November, Reuters/Ipsos polling showed this week.

Biden has opted against attending the annual conference in recent years but Harris is scheduled on Friday to deliver what aides have billed as a major speech on “the importance of fulfilling the U.S. role of global leadership” before meeting with U.S. lawmakers, Ukrainian President Volodymyr Zelenskiy and German Chancellor Olaf Scholz.

Harris is likely to be closely watched for her ability to lead after a Department of Justice special counsel report last week described Biden, 81, as an elderly man with a “poor memory.” Trump is 77.

The conference comes as conflict between Russia and the West has brought war to a continent that has spent decades trying to forge peace, underwritten by U.S. security commitments to the NATO security alliance that Trump has threatened to jettison.

The Senate on Tuesday approved a $95.34 billion military aid package for Ukraine and other countries, but the funding may never be put up for a vote in the Republican-controlled House of Representative because of Trump’s opposition.

Trump made a reference during a political rally in South Carolina on Saturday about what he called “delinquent” payments by NATO members and recounted what he said was a past conversation with the head of “a big country” about a potential attack by Russia.

“No, I would not protect you. In fact I would encourage them (Russia) to do whatever the hell they want. You gotta pay,” Trump said he told the unnamed leader.

The NATO treaty contains a provision that guarantees mutual defense of member states if one is attacked.

Biden condemned Trump’s comments as an invitation for Putin to invade allies and said they underscored the urgent need for Ukraine funding.

Jeremy Shapiro, a research director at the European Council on Foreign Relations, said he did not expect Harris or Blinken to make any promises at the conference about what a prospective Trump administration might do.

“They’re going to give a simple message: We’re going to win the election,” Shapiro said.

(This story has been refiled to add dropped first name and title for Trump in paragraph 2)