The United States is pledging an urgent $50 million in emergency funds, which is part of a $300 million package in assistance to address urgent humanitarian needs resulting from the crisis in South Sudan, according to Reuters.

President Barack Obama authorized the emergency funding ahead of a South Sudan pledging conference scheduled for Tuesday in Oslo, Norway, Reuters reported. The $50 million will be part of a package of nearly $300 million in additional assistance that the United States will formally pledge on Tuesday at a conference in Oslo.

It brings the total of U.S. humanitarian assistance to about $434 million since the conflict began in December, according to Reuters. Norway also pledged $63 million in aid on Monday.

The $50 million will support the U.N. High Commission for Refugees and its partners to help more than 300,000 refugees who have crossed into Ethiopia, Kenya, Sudan and Uganda, as well as internally displaced people, the statement said, according to Reuters.

Some of the money will come from the U.S. Emergency Refugee and Migration Assistance Fund and will be used to support the United Nations and other refugee organizations, Reuters reported.

The White House says months of conflict between South Sudan's government and rebel forces have left the country at risk of famine unless humanitarian agencies increase their assistance, according to Reuters.

The White House says the UN and its partners are urgently assisting the more than 300,000 refugees that have crossed into Ethiopia, Kenya, Sudan and Uganda, as well as internally-displaced persons in South Sudan, according to Reuters.

More than 1.3 million people have been displaced, and South Sudan is at risk of famine, the White House said, Reuters reported.

"Months of conflict between the government of South Sudan and rebel forces have exacted a terrible toll on the people of South Sudan," White House National Security Council spokeswoman Caitlin Hayden said in a statement, according to Reuters.