U.S. Senator Lindsey Graham
U.S. Senator Lindsey GrahamReuters

Senator Lindsey Graham (R-SC), who in recent months has moved closer to running for president, will provide a "very important update" on his plans Monday morning, he told supporters on Sunday, according to The Washington Post.

"Tomorrow morning I will be giving a very important update on my 2016 plans and I want to make sure you are able to hear it," Graham wrote in an e-mail to his supporters, the report said.

Graham added said he will appear on CBS's "This Morning" at 8:00 a.m. Eastern time for the announcement.

"As an announcement draws near, I need to know you stand with me," he continued, linking to a page where people can donate money to his exploratory committee.

Graham formed the committee, Security Through Strength, in January and has been staffing it as he prepares for what looks increasingly like it will become a full-fledged run for president.

A Graham spokesperson did not immediately respond to a question about his plans.

If Graham runs, he is likely to center his campaign around the theme of national security, noted The Washington Post. He is among the most hawkish figures in the Republican Party and already has secured the support of Sen. John McCain (R-AZ), a close friend and fellow hawk.

If he announces a presidential run, Graham would be joining Marco Rubio, Ted Cruz and Rand Paul who have already announced their intention to run for the GOP nomination. Another possible candidate is former Florida Governor Jeb Bush, who has yet to announce his candidacy.

Graham, who has visited Israel numerous times, most recently in late December, has expressed his support for the Jewish state.

In January, speaking with the Israel Hayom newspaper, Graham assured Israel that Congress has its back on issues such as a deal with Iran and peace with the Palestinian Authority.

"I just want the Israeli people to know that Congress does have your back. I am by no means anti-Palestinian. I am pro-Israel and I want to help the Palestinian people with their legitimate ambitions," clarified Graham.