President Obama called Florida Gov. Rick Scott (R) on Sunday, offering the federal government's help in responding to Tropical Storm Isaac, which is closing in on the state.

"The President told the Governor the people of Florida are in his thoughts during this time," said a readout of the call from the White House.

Obama told Scott the federal government was ready to help provide any assistance the state needed, including for efforts to ensure the safety of visitors to the Republican National Convention in Tampa.

Republicans already called off the first day of their convention, which was scheduled to start on Monday, due to the storm. Republican National Committee Chairman Reince Priebus on Sunday said organizers were planning on holding events on Tuesday and were drafting an updated schedule for the convention.

Scott declared a state of emergency in Florida on Saturday, a step that will help federal and state officials coordinate their response.

The White House said Obama also received a briefing on Sunday from Craig Fugate, the administrator of the Federal Emergency Management Agency (FEMA) and Dr. Rick Knabb, director of the National Hurricane Center on the "projected track and timing of the storm as well as steps being taken by the Administration to support potentially impacted states." 

Obama asked Fugate to continue coordinating preparations with state and local officials in communities that could be impacted by the story. FEMA has sent teams to Florida and Louisiana to support local officials, according to the White House. Federal officials are also in close communication with Alabama, Mississippi and other southeastern states.

The National Weather Service issued a hurricane warning for the Florida Keys and portions of the state's west coast. A hurricane watch is also in effect for the southeastern part of the state.

Fugate urged residents to closely monitor the government's weather radio and local news.

"As Tropical Storm Isaac continues towards Florida and the Gulf States, local residents need to monitor storm conditions and follow the direction of local officials," Fugate said in a statement.

FEMA urged residents fill their cars' gas tanks, withdraw cash and plan an evacuation route. Residents can visit the agency's website for more information.

FEMA emphasized that it has millions of liters of water, millions of meals and hundreds of thousands of blankets located at distribution centers around the country, including in Atlanta, Ga. and Dallas, Texas.

This story was posted at 2:23 p.m. and has been updated.